diff --git a/tests/uts/dbFormhandler_BaseTest.php b/tests/uts/dbFormhandler_BaseTest.php
index dc87c32..b88094a 100644
--- a/tests/uts/dbFormhandler_BaseTest.php
+++ b/tests/uts/dbFormhandler_BaseTest.php
@@ -8,33 +8,33 @@ public function testConstructor(): void
     {
         $form = new dbFormHandler();
 
-        $this->assertInstanceOf("dbFormHandler", $form);
+        static::assertInstanceOf("dbFormHandler", $form);
 
         $_sql = $this->getPrivateProperty($form, '_sql');
-        $this->assertTrue(is_array($_sql));
-        $this->assertEquals(0, sizeof($_sql));
+        static::assertTrue(is_array($_sql));
+        static::assertEquals(0, sizeof($_sql));
 
         $_dbData = $this->getPrivateProperty($form, '_dbData');
-        $this->assertTrue(is_array($_dbData));
-        $this->assertEquals(0, sizeof($_dbData));
+        static::assertTrue(is_array($_dbData));
+        static::assertEquals(0, sizeof($_dbData));
 
         $_dontSave = $this->getPrivateProperty($form, '_dontSave');
-        $this->assertTrue(is_array($_dontSave));
-        $this->assertEquals(0, sizeof($_dontSave));
+        static::assertTrue(is_array($_dontSave));
+        static::assertEquals(0, sizeof($_dontSave));
 
         $_id = $this->getPrivateProperty($form, '_id');
-        $this->assertTrue(is_array($_id));
-        $this->assertEquals(0, sizeof($_id));
+        static::assertTrue(is_array($_id));
+        static::assertEquals(0, sizeof($_id));
 
         $dieOnQuery = $this->getPrivateProperty($form, 'dieOnQuery');
-        $this->assertFalse($dieOnQuery);
+        static::assertFalse($dieOnQuery);
 
         $_editName = $this->getPrivateProperty($form, '_editName');
-        $this->assertEquals("id", $_editName);
+        static::assertEquals("id", $_editName);
 
-        $this->assertTrue($form->insert);
-        $this->assertFalse($form->edit);
-        $this->assertFalse($form->isPosted());
+        static::assertTrue($form->insert);
+        static::assertFalse($form->edit);
+        static::assertFalse($form->isPosted());
     }
 
     public function test_SetConnectionResource(): void
@@ -44,12 +44,12 @@ public function test_SetConnectionResource(): void
         $this->setConnectedTable($form, "test");
 
         $_db = $this->getPrivateProperty($form, '_db');
-        $this->assertInstanceOf("YadalDibi", $_db);
+        static::assertInstanceOf("YadalDibi", $_db);
 
-        $this->assertTrue($_db->isConnected());
-        $this->assertTrue($_db->_quoteNumbers);
+        static::assertTrue($_db->isConnected());
+        static::assertTrue($_db->_quoteNumbers);
 
         $_table = $this->getPrivateProperty($form, '_table');
-        $this->assertEquals("test", $_table);
+        static::assertEquals("test", $_table);
     }
 };
diff --git a/tests/uts/dbFormhandler_PassFieldTest.php b/tests/uts/dbFormhandler_PassFieldTest.php
index 421d69b..14a8abf 100644
--- a/tests/uts/dbFormhandler_PassFieldTest.php
+++ b/tests/uts/dbFormhandler_PassFieldTest.php
@@ -10,19 +10,19 @@ public function test_new(): void
 
         $form = new dbFormHandler();
 
-        $this->assertTrue($form->insert);
-        $this->assertFalse($form->edit);
-        $this->assertFalse($form->isPosted());
+        static::assertTrue($form->insert);
+        static::assertFalse($form->edit);
+        static::assertFalse($form->isPosted());
 
         $this->setConnectedTable($form, "test");
 
         $form->passField("Your password", "pass", FH_PASSWORD);
         $form->textField("TextNullable", "textNullable");
 
-        $this->assertEmpty($form->getValue("textNullable"));
-        $this->assertEmpty($form->getValue("textNotNullable"));
+        static::assertEmpty($form->getValue("textNullable"));
+        static::assertEmpty($form->getValue("textNotNullable"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Your password:<input type="password" name="pass" id="pass" size="20" />error_pass',
             'TextNullable:<input type="text" name="textNullable" id="textNullable" value="" size="20" />error_textNullable'
         ]);
@@ -36,9 +36,9 @@ public function test_edit(): void
 
         $form = new dbFormHandler();
 
-        $this->assertFalse($form->insert);
-        $this->assertTrue($form->edit);
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->insert);
+        static::assertTrue($form->edit);
+        static::assertFalse($form->isPosted());
 
         $this->getDatabaseMock()
             ->expects($this->exactly(1))
@@ -52,10 +52,10 @@ public function test_edit(): void
         $form->passField("Your password", "pass", FH_PASSWORD);
         $form->textField("TextNullable", "textNullable");
 
-        $this->assertEquals("text1", $form->getValue("textNullable"));
-        $this->assertEquals("secret", $form->getValue("pass"));
+        static::assertEquals("text1", $form->getValue("textNullable"));
+        static::assertEquals("secret", $form->getValue("pass"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Your password:<input type="password" name="pass" id="pass" size="20" />error_pass',
             'TextNullable:<input type="text" name="textNullable" id="textNullable" value="text1" size="20" />error_textNullable'
         ]);
@@ -67,9 +67,9 @@ public function test_insert_noValues(): void
 
         $form = new dbFormHandler();
 
-        $this->assertTrue($form->insert);
-        $this->assertFalse($form->edit);
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->insert);
+        static::assertFalse($form->edit);
+        static::assertTrue($form->isPosted());
 
         $this->setConnectedTable($form, "test");
 
@@ -78,7 +78,7 @@ public function test_insert_noValues(): void
         $e = $form->catchErrors();
 
         $expected  = "You did not enter a correct value for this field!";
-        $this->assertStringContainsString($expected, $e['pass']);
+        static::assertStringContainsString($expected, $e['pass']);
     }
 
     public function test_insert(): void
@@ -91,9 +91,9 @@ public function test_insert(): void
 
         $form = new dbFormHandler();
 
-        $this->assertTrue($form->insert);
-        $this->assertFalse($form->edit);
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->insert);
+        static::assertFalse($form->edit);
+        static::assertTrue($form->isPosted());
 
         $this->setConnectedTable($form, "test");
 
@@ -111,7 +111,7 @@ public function test_insert(): void
 
         $r = $form->flush(true);
 
-        $this->assertEmpty($r);
+        static::assertEmpty($r);
         $this->assertSavedId(4711);
         $this->assertSavedValue('secret', 'pass');
         $this->assertSavedValue('thetext', 'textNullable');
@@ -126,8 +126,8 @@ public function test_insert(): void
 
     //     $form = new dbFormHandler();
 
-    //     $this->assertFalse($form->insert);
-    //     $this->assertTrue($form->edit);
+    //     static::assertFalse($form->insert);
+    //     static::assertTrue($form->edit);
 
     //     $this->getDatabaseMock()
     //             ->expects($this->exactly(1))
@@ -149,9 +149,9 @@ public function test_insert(): void
 
     //     $r = $form->flush(true);
 
-    //     $this->fail("forced failure: empty pass fails");
+    //     static::fail("forced failure: empty pass fails");
 
-    //     $this->assertEquals("", $r);
+    //     static::assertEquals("", $r);
     //     $this->assertSavedId(4714);
     //     $this->assertSavedValueEmtpy('textNullable');
     // }
@@ -166,9 +166,9 @@ public function test_update(): void
 
         $form = new dbFormHandler();
 
-        $this->assertFalse($form->insert);
-        $this->assertTrue($form->edit);
-        $this->assertTrue($form->isPosted());
+        static::assertFalse($form->insert);
+        static::assertTrue($form->edit);
+        static::assertTrue($form->isPosted());
 
         $this->getDatabaseMock()
             ->expects($this->exactly(1))
@@ -190,7 +190,7 @@ public function test_update(): void
 
         $r = $form->flush(true);
 
-        $this->assertEmpty($r);
+        static::assertEmpty($r);
         $this->assertSavedId(4715);
         $this->assertSavedValue("newpass", "pass");
     }
diff --git a/tests/uts/dbFormhandler_TextFieldTest.php b/tests/uts/dbFormhandler_TextFieldTest.php
index cc4dc0e..a9a2229 100644
--- a/tests/uts/dbFormhandler_TextFieldTest.php
+++ b/tests/uts/dbFormhandler_TextFieldTest.php
@@ -10,19 +10,19 @@ public function test_new(): void
 
         $form = new dbFormHandler();
 
-        $this->assertTrue($form->insert);
-        $this->assertFalse($form->edit);
-        $this->assertFalse($form->isPosted());
+        static::assertTrue($form->insert);
+        static::assertFalse($form->edit);
+        static::assertFalse($form->isPosted());
 
         $this->setConnectedTable($form, "test");
 
         $form->textField("TextNullable", "textNullable");
         $form->textField("TextNotNullable", "textNotNullable");
 
-        $this->assertEmpty($form->getValue("textNullable"));
-        $this->assertEmpty($form->getValue("textNotNullable"));
+        static::assertEmpty($form->getValue("textNullable"));
+        static::assertEmpty($form->getValue("textNotNullable"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'input type="text" name="textNullable" id="textNullable" value=""',
             'input type="text" name="textNotNullable" id="textNotNullable" value=""'
         ]);
@@ -36,9 +36,9 @@ public function test_edit_noDataset(): void
 
         $form = new dbFormHandler();
 
-        $this->assertFalse($form->insert);
-        $this->assertTrue($form->edit);
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->insert);
+        static::assertTrue($form->edit);
+        static::assertFalse($form->isPosted());
 
         $this->getDatabaseMock()
             ->expects($this->exactly(1))
@@ -57,9 +57,9 @@ public function test_edit(): void
 
         $form = new dbFormHandler();
 
-        $this->assertFalse($form->insert);
-        $this->assertTrue($form->edit);
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->insert);
+        static::assertTrue($form->edit);
+        static::assertFalse($form->isPosted());
 
         $this->getDatabaseMock()
             ->expects($this->exactly(1))
@@ -73,10 +73,10 @@ public function test_edit(): void
         $form->textField("TextNullable", "textNullable");
         $form->textField("TextNotNullable", "textNotNullable");
 
-        $this->assertEquals("text1", $form->getValue("textNullable"));
-        $this->assertEquals("text2", $form->getValue("textNotNullable"));
+        static::assertEquals("text1", $form->getValue("textNullable"));
+        static::assertEquals("text2", $form->getValue("textNotNullable"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'input type="text" name="textNullable" id="textNullable" value="text1"',
             'input type="text" name="textNotNullable" id="textNotNullable" value="text2"'
         ]);
@@ -90,9 +90,9 @@ public function test_insert_noValues(): void
 
         $form = new dbFormHandler();
 
-        $this->assertTrue($form->insert);
-        $this->assertFalse($form->edit);
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->insert);
+        static::assertFalse($form->edit);
+        static::assertTrue($form->isPosted());
 
         $this->setConnectedTable($form, "test");
 
@@ -109,7 +109,7 @@ public function test_insert_noValues(): void
 
         $r = $form->flush(true);
 
-        $this->assertEmpty($r);
+        static::assertEmpty($r);
         $this->assertSavedId(4712);
         $this->assertSavedValueEmtpy('textNullable');
         $this->assertSavedValueEmtpy('textNotNullable');
@@ -125,9 +125,9 @@ public function test_insert(): void
 
         $form = new dbFormHandler();
 
-        $this->assertTrue($form->insert);
-        $this->assertFalse($form->edit);
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->insert);
+        static::assertFalse($form->edit);
+        static::assertTrue($form->isPosted());
 
         $this->setConnectedTable($form, "test");
 
@@ -144,7 +144,7 @@ public function test_insert(): void
 
         $r = $form->flush(true);
 
-        $this->assertEmpty($r);
+        static::assertEmpty($r);
         $this->assertSavedId(4713);
         $this->assertSavedValue('thetext', 'textNullable');
         $this->assertSavedValue('anothertext', 'textNotNullable');
@@ -159,9 +159,9 @@ public function test_update_noValues(): void
 
         $form = new dbFormHandler();
 
-        $this->assertFalse($form->insert);
-        $this->assertTrue($form->edit);
-        $this->assertTrue($form->isPosted());
+        static::assertFalse($form->insert);
+        static::assertTrue($form->edit);
+        static::assertTrue($form->isPosted());
 
         $this->getDatabaseMock()
             ->expects($this->exactly(1))
@@ -183,7 +183,7 @@ public function test_update_noValues(): void
 
         $r = $form->flush(true);
 
-        $this->assertEmpty($r);
+        static::assertEmpty($r);
         $this->assertSavedId(4714);
         $this->assertSavedValueEmtpy('textNullable');
         $this->assertSavedValueEmtpy('textNotNullable');
@@ -200,9 +200,9 @@ public function test_update(): void
 
         $form = new dbFormHandler();
 
-        $this->assertFalse($form->insert);
-        $this->assertTrue($form->edit);
-        $this->assertTrue($form->isPosted());
+        static::assertFalse($form->insert);
+        static::assertTrue($form->edit);
+        static::assertTrue($form->isPosted());
 
         $this->getDatabaseMock()
             ->expects($this->exactly(1))
@@ -223,7 +223,7 @@ public function test_update(): void
 
         $r = $form->flush(true);
 
-        $this->assertEmpty($r);
+        static::assertEmpty($r);
         $this->assertSavedId(4715);
         $this->assertSavedValue('thetext', 'textNullable');
         $this->assertSavedValue('anothertext', 'textNotNullable');
diff --git a/tests/uts/dbFormhandler_dbListFieldTest.php b/tests/uts/dbFormhandler_dbListFieldTest.php
index 95c93a7..e3e4672 100644
--- a/tests/uts/dbFormhandler_dbListFieldTest.php
+++ b/tests/uts/dbFormhandler_dbListFieldTest.php
@@ -10,19 +10,19 @@ public function test_new(): void
 
         $form = new dbFormHandler();
 
-        $this->assertTrue($form->insert);
-        $this->assertFalse($form->edit);
-        $this->assertFalse($form->isPosted());
+        static::assertTrue($form->insert);
+        static::assertFalse($form->edit);
+        static::assertFalse($form->isPosted());
 
         $this->setConnectedTable($form, "test");
 
         $form->textField("TextNullable", "textNullable");
         $form->textField("TextNotNullable", "textNotNullable");
 
-        $this->assertEmpty($form->getValue("textNullable"));
-        $this->assertEmpty($form->getValue("textNotNullable"));
+        static::assertEmpty($form->getValue("textNullable"));
+        static::assertEmpty($form->getValue("textNotNullable"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'input type="text" name="textNullable" id="textNullable" value=""',
             'input type="text" name="textNotNullable" id="textNotNullable" value=""'
         ]);
@@ -36,9 +36,9 @@ public function test_edit_noDataset(): void
 
         $form = new dbFormHandler();
 
-        $this->assertFalse($form->insert);
-        $this->assertTrue($form->edit);
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->insert);
+        static::assertTrue($form->edit);
+        static::assertFalse($form->isPosted());
 
         $this->getDatabaseMock()
             ->expects($this->exactly(1))
@@ -57,9 +57,9 @@ public function test_edit(): void
 
         $form = new dbFormHandler();
 
-        $this->assertFalse($form->insert);
-        $this->assertTrue($form->edit);
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->insert);
+        static::assertTrue($form->edit);
+        static::assertFalse($form->isPosted());
 
         $this->getDatabaseMock()
             ->expects($this->exactly(1))
@@ -73,10 +73,10 @@ public function test_edit(): void
         $form->textField("TextNullable", "textNullable");
         $form->textField("TextNotNullable", "textNotNullable");
 
-        $this->assertEquals("text1", $form->getValue("textNullable"));
-        $this->assertEquals("text2", $form->getValue("textNotNullable"));
+        static::assertEquals("text1", $form->getValue("textNullable"));
+        static::assertEquals("text2", $form->getValue("textNotNullable"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'input type="text" name="textNullable" id="textNullable" value="text1"',
             'input type="text" name="textNotNullable" id="textNotNullable" value="text2"'
         ]);
@@ -90,9 +90,9 @@ public function test_insert_noValues(): void
 
         $form = new dbFormHandler();
 
-        $this->assertTrue($form->insert);
-        $this->assertFalse($form->edit);
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->insert);
+        static::assertFalse($form->edit);
+        static::assertTrue($form->isPosted());
 
         $this->setConnectedTable($form, "test");
 
@@ -109,7 +109,7 @@ public function test_insert_noValues(): void
 
         $r = $form->flush(true);
 
-        $this->assertEmpty($r);
+        static::assertEmpty($r);
         $this->assertSavedId(4712);
         $this->assertSavedValueEmtpy('textNullable');
         $this->assertSavedValueEmtpy('textNotNullable');
@@ -125,9 +125,9 @@ public function test_insert(): void
 
         $form = new dbFormHandler();
 
-        $this->assertTrue($form->insert);
-        $this->assertFalse($form->edit);
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->insert);
+        static::assertFalse($form->edit);
+        static::assertTrue($form->isPosted());
 
         $this->setConnectedTable($form, "test");
 
@@ -144,7 +144,7 @@ public function test_insert(): void
 
         $r = $form->flush(true);
 
-        $this->assertEmpty($r);
+        static::assertEmpty($r);
         $this->assertSavedId(4713);
         $this->assertSavedValue('thetext', 'textNullable');
         $this->assertSavedValue('anothertext', 'textNotNullable');
@@ -159,9 +159,9 @@ public function test_update_noValues(): void
 
         $form = new dbFormHandler();
 
-        $this->assertFalse($form->insert);
-        $this->assertTrue($form->edit);
-        $this->assertTrue($form->isPosted());
+        static::assertFalse($form->insert);
+        static::assertTrue($form->edit);
+        static::assertTrue($form->isPosted());
 
         $this->getDatabaseMock()
             ->expects($this->exactly(1))
@@ -183,7 +183,7 @@ public function test_update_noValues(): void
 
         $r = $form->flush(true);
 
-        $this->assertEmpty($r);
+        static::assertEmpty($r);
         $this->assertSavedId(4714);
         $this->assertSavedValueEmtpy('textNullable');
         $this->assertSavedValueEmtpy('textNotNullable');
@@ -200,9 +200,9 @@ public function test_update(): void
 
         $form = new dbFormHandler();
 
-        $this->assertFalse($form->insert);
-        $this->assertTrue($form->edit);
-        $this->assertTrue($form->isPosted());
+        static::assertFalse($form->insert);
+        static::assertTrue($form->edit);
+        static::assertTrue($form->isPosted());
 
         $this->getDatabaseMock()
             ->expects($this->exactly(1))
@@ -223,7 +223,7 @@ public function test_update(): void
 
         $r = $form->flush(true);
 
-        $this->assertEmpty($r);
+        static::assertEmpty($r);
         $this->assertSavedId(4715);
         $this->assertSavedValue('thetext', 'textNullable');
         $this->assertSavedValue('anothertext', 'textNotNullable');
diff --git a/tests/uts/dbFormhandler_dbSelectFieldTest.php b/tests/uts/dbFormhandler_dbSelectFieldTest.php
index 5628d50..b17fafe 100644
--- a/tests/uts/dbFormhandler_dbSelectFieldTest.php
+++ b/tests/uts/dbFormhandler_dbSelectFieldTest.php
@@ -34,7 +34,7 @@ public function test_new(): void
             '</select>error_saveInField'
         ];
 
-        $this->assertFormFlushContains($form, $aExpected);
+        static::assertFormFlushContains($form, $aExpected);
     }
 
     public function test_edit(): void
@@ -45,9 +45,9 @@ public function test_edit(): void
 
         $form = new dbFormHandler();
 
-        $this->assertFalse($form->insert);
-        $this->assertTrue($form->edit);
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->insert);
+        static::assertTrue($form->edit);
+        static::assertFalse($form->isPosted());
 
         $this->getDatabaseMock()
             ->expects($this->exactly(1))
@@ -75,7 +75,7 @@ public function test_edit(): void
             FH_NOT_EMPTY
         );
 
-        $this->assertEquals("2", $form->getValue("saveInField"));
+        static::assertEquals("2", $form->getValue("saveInField"));
 
         $aExpected = [
             'Options from a table:<select name="saveInField" id="saveInField" size="1">',
@@ -84,7 +84,7 @@ public function test_edit(): void
             '</select>error_saveInField'
         ];
 
-        $a = $this->assertFormFlushContains($form, $aExpected);
+        $a = static::assertFormFlushContains($form, $aExpected);
     }
 
     public function test_insert(): void
@@ -97,7 +97,7 @@ public function test_insert(): void
         $this->setConnectedTable($form, "test");
         $this->createMocksForTable();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $this->getDatabaseMock()
             ->expects($this->once())
@@ -127,7 +127,7 @@ public function test_insert(): void
 
         $r = $form->flush(true);
 
-        $this->assertEquals("", $r);
+        static::assertEquals("", $r);
         $this->assertSavedId(4711);
         $this->assertSavedValue('2', 'saveInField');
     }
@@ -172,11 +172,11 @@ public function test_insert(): void
 
     //     $r = $form->flush(true);
 
-    //     $this->assertEquals("", $r);
+    //     static::assertEquals("", $r);
     //     $this->assertSavedId(4711);
     //     $this->assertSavedValue('3', 'saveInField');
 
-    //     $this->fail("forced failure: wrong value will be saved. 3 is not in list.");
+    //     static::fail("forced failure: wrong value will be saved. 3 is not in list.");
     // }
 
     public function test_update(): void
@@ -189,9 +189,9 @@ public function test_update(): void
 
         $form = new dbFormHandler();
 
-        $this->assertFalse($form->insert);
-        $this->assertTrue($form->edit);
-        $this->assertTrue($form->isPosted());
+        static::assertFalse($form->insert);
+        static::assertTrue($form->edit);
+        static::assertTrue($form->isPosted());
 
         $this->getDatabaseMock()
             ->expects($this->exactly(1))
@@ -230,7 +230,7 @@ public function test_update(): void
 
         $r = $form->flush(true);
 
-        $this->assertEquals("", $r);
+        static::assertEquals("", $r);
         $this->assertSavedId(123);
         $this->assertSavedValue('2', 'saveInField');
     }
@@ -240,7 +240,7 @@ public function test_multiple_new(): void
         $form = new dbFormHandler();
 
         $this->setConnectedTable($form, "test");
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $this->getDatabaseMock()
             ->expects($this->once())
@@ -267,7 +267,7 @@ public function test_multiple_new(): void
             '</select>error_saveInFieldString'
         ];
 
-        $this->assertFormFlushContains($form, $aExpected);
+        static::assertFormFlushContains($form, $aExpected);
     }
 
     // public function test_multiple_edit(): void
@@ -278,8 +278,8 @@ public function test_multiple_new(): void
 
     //     $form = new dbFormHandler();
 
-    //     $this->assertFalse($form->insert);
-    //     $this->assertTrue($form->edit);
+    //     static::assertFalse($form->insert);
+    //     static::assertTrue($form->edit);
 
     //     $this->getDatabaseMock()
     //             ->expects($this->exactly(1))
@@ -308,7 +308,7 @@ public function test_multiple_new(): void
     //         true
     //     );
 
-    //     $this->assertEquals(['0' => "2", '1' => " 1"], $form->getValue("saveInFieldString"));
+    //     static::assertEquals(['0' => "2", '1' => " 1"], $form->getValue("saveInFieldString"));
 
     //     $aExpected = [
     //         'Options from a table:<select name="saveInFieldString[]" id="saveInFieldString" size="4" multiple="multiple">',
@@ -317,9 +317,9 @@ public function test_multiple_new(): void
     //         '</select>error_saveInFieldString'
     //     ];
 
-    //     $a = $this->assertFormFlushContains($form, $aExpected);
+    //     $a = static::assertFormFlushContains($form, $aExpected);
 
-    //     $this->fail("forced failure: getValue has to deliver trimmed values, not ' 1'");
+    //     static::fail("forced failure: getValue has to deliver trimmed values, not ' 1'");
     // }
 
     public function test_multiple_insert(): void
@@ -329,7 +329,7 @@ public function test_multiple_insert(): void
 
         $form = new dbFormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $this->setConnectedTable($form, "test");
         $this->createMocksForTable();
@@ -362,7 +362,7 @@ public function test_multiple_insert(): void
 
         $r = $form->flush(true);
 
-        $this->assertEquals("", $r);
+        static::assertEquals("", $r);
         $this->assertSavedId(4711);
         $this->assertSavedValue(['0' => "2", '1' => "1"], 'saveInFieldString');
     }
@@ -376,7 +376,7 @@ public function test_multiple_update(): void
 
         $form = new dbFormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $this->getDatabaseMock()
             ->expects($this->exactly(1))
@@ -415,7 +415,7 @@ public function test_multiple_update(): void
 
         $r = $form->flush(true);
 
-        $this->assertEquals("", $r);
+        static::assertEquals("", $r);
         $this->assertSavedId(123);
         $this->assertSavedValue(['0' => "2"], 'saveInFieldString');
     }
diff --git a/tests/uts/formhandler_AutocompleteTest.php b/tests/uts/formhandler_AutocompleteTest.php
index 461dca5..526946b 100644
--- a/tests/uts/formhandler_AutocompleteTest.php
+++ b/tests/uts/formhandler_AutocompleteTest.php
@@ -14,7 +14,7 @@ public function test_show(): void
 
         $form->setAutoComplete("textfield", $aOptions);
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'FHTML/js/autocomplete.js',
             'textfield_values = ["first", "second", "third"];',
             'Textfield:<input type="text" name="textfield" id="textfield" value="" size="20"   onkeypress=\'return FH_autocomplete(this, event, textfield_values);\'  />error_textfield'
@@ -53,7 +53,7 @@ public function test_after_show(): void
 
         $form->setAutoCompleteAfter("textfield", "@", $aOptions);
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'FHTML/js/autocomplete.js',
             'textfield_values = ["first", "second", "third"];',
             'Textfield:<input type="text" name="textfield" id="textfield" value="" size="20"   onkeypress=\'return autocompleteafter(this, event,"@", textfield_values);\'  />error_textfield'
diff --git a/tests/uts/formhandler_BrowserFieldTest.php b/tests/uts/formhandler_BrowserFieldTest.php
index 4952e33..ff64c5b 100644
--- a/tests/uts/formhandler_BrowserFieldTest.php
+++ b/tests/uts/formhandler_BrowserFieldTest.php
@@ -10,7 +10,7 @@ public function test_new(): void
 
         $form->browserField("BrowserField", "browserfield", "a/path");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'BrowserField:<input type="text" name="browserfield" id="browserfield" value="" size="20" /> <input type="button" name="Bladeren" id="Bladeren" value="Bladeren"',
             'onclick="window.open(',
             'FHTML/filemanager/browser/default/browser.html?Type=File&naam=browserfield&Connector=../../connectors/php/connector.php?ServerPath=a/path\',\'\',\'modal=yes,width=650,height=400\');" /> error_browserfield'
@@ -24,7 +24,7 @@ public function test_viewmode(): void
         $form->browserField("BrowserField", "browserfield", "a/path");
         $form->setFieldViewMode("browserfield");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'BrowserField:error_browserfield'
         ]);
     }
@@ -38,9 +38,9 @@ public function test_posted(): void
 
         $form->browserField("BrowserField", "browserfield", "a/path");
 
-        $this->assertEquals("o1", $form->getValue("browserfield"));
+        static::assertEquals("o1", $form->getValue("browserfield"));
 
-        $this->assertTrue($form->isCorrect());
+        static::assertTrue($form->isCorrect());
     }
 
 
diff --git a/tests/uts/formhandler_ButtonsTest.php b/tests/uts/formhandler_ButtonsTest.php
index a677da2..118513c 100644
--- a/tests/uts/formhandler_ButtonsTest.php
+++ b/tests/uts/formhandler_ButtonsTest.php
@@ -12,7 +12,7 @@ public function test_button(): void
         $form->button("Button2", "button4711");
         $form->button("Button3", null, 'data-old="123"');
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             '<input type="button" name="button1" id="button1" value="Button" />error_button1',
             '<input type="button" name="button4711" id="button4711" value="Button2" />error_button4711',
             '<input type="button" name="button2" id="button2" value="Button3" data-old="123" />error_button2'
@@ -29,7 +29,7 @@ public function test_button_setIndex(): void
 
         $form->setTabIndex(array("but2", "but1", "but3"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             '<input type="button" name="but1" id="but1" value="Button" tabindex="2" />error_but1',
             '<input type="button" name="but2" id="but2" value="Button2" tabindex="1" />error_but2',
             '<input type="button" name="but3" id="but3" value="Button3" tabindex="3" />error_but3'
@@ -46,7 +46,7 @@ public function test_submitButtom(): void
         $form->submitButton(null, null, 'data-old="123"');
         $form->submitButton(null, null, null, false);
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             '<input type="submit" value="Submit" name="button1" id="button1"  onclick=" if (this.form.querySelector(\':invalid\') == null) { this.form.submit();this.disabled=true;}"  />error_button1',
             '<input type="submit" value="Caption" name="button2" id="button2"  onclick=" if (this.form.querySelector(\':invalid\') == null) { this.form.submit();this.disabled=true;}"  />error_button2',
             '<input type="submit" value="Submit" name="submitbutton" id="submitbutton"  onclick=" if (this.form.querySelector(\':invalid\') == null) { this.form.submit();this.disabled=true;}"  />error_submitbutton',
@@ -61,7 +61,7 @@ public function test_submitButtom_onClick(): void
 
         $form->submitButton("Caption", "submitbutton", "onClick='doIt()'");
 
-        $this->assertFormFlushContains($form, ['<input type="submit" value="Caption" name="submitbutton" id="submitbutton"  onclick=\'this.form.submit();this.disabled=true;doIt()\' />error_submitbutton']);
+        static::assertFormFlushContains($form, ['<input type="submit" value="Caption" name="submitbutton" id="submitbutton"  onclick=\'this.form.submit();this.disabled=true;doIt()\' />error_submitbutton']);
     }
 
     public function test_imageButton(): void
@@ -72,7 +72,7 @@ public function test_imageButton(): void
         $form->imageButton("image.gif", "imagebutton");
         $form->imageButton("image.gif", null, 'data-old="123"');
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             '<input type="image" src="image.gif" name="button1" id="button1" />error_button1',
             '<input type="image" src="image.gif" name="imagebutton" id="imagebutton" />error_imagebutton',
             '<input type="image" src="image.gif" name="button2" id="button2" data-old="123" />error_button2'
@@ -88,7 +88,7 @@ public function test_resetButton(): void
         $form->resetButton(null, "resetbutton");
         $form->resetButton(null, null, 'data-old="123"');
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             '<input type="reset" value="Reset" name="button1" id="button1" />error_button1',
             '<input type="reset" value="Resetbutton" name="button2" id="button2" />error_button2',
             '<input type="reset" value="Reset" name="resetbutton" id="resetbutton" />error_resetbutton',
@@ -106,7 +106,7 @@ public function test_cancelButton(): void
         $form->cancelButton(null, null, "cancelbutton");
         $form->cancelButton(null, null, null, 'data-old="123"');
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             '<input type="button" name="button1" id="button1" value="Cancel"  onclick="history.back(-1)" />error_button1',
             '<input type="button" name="button2" id="button2" value="CancelButton"  onclick="history.back(-1)" />error_button2',
             '<input type="button" name="button3" id="button3" value="Cancel"  onclick="document.location.href=\'backurl\'" />error_button3',
@@ -124,7 +124,7 @@ public function test_backButton(): void
         $form->backButton(null, "backbutton");
         $form->backButton(null, null, 'data-old="123"');
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             '<input type="button" name="button1" id="button1" value="Back"  onclick="pageBack(document.forms[\'FormHandler\']);" />error_button1',
             '<input type="button" name="button2" id="button2" value="BackButton"  onclick="pageBack(document.forms[\'FormHandler\']);" />error_button2',
             '<input type="button" name="backbutton" id="backbutton" value="Back"  onclick="pageBack(document.forms[\'FormHandler\']);" />error_backbutton',
diff --git a/tests/uts/formhandler_CaptchaFieldTest.php b/tests/uts/formhandler_CaptchaFieldTest.php
index b8bf472..75433c0 100644
--- a/tests/uts/formhandler_CaptchaFieldTest.php
+++ b/tests/uts/formhandler_CaptchaFieldTest.php
@@ -8,13 +8,13 @@ public function test_new(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->CaptchaField("Captchafield", "captchafield");
 
-        $this->assertEmpty($form->getValue("captchafield"));
+        static::assertEmpty($form->getValue("captchafield"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             '<input type="image" src="',
             'FHTML/securimage/securimage_show.php?sid=',
             'name="button1" id="button1" onclick="return false;" style="cursor:default;" />error_button1Captchafield:<input type="text" name="captchafield" id="captchafield" value="" size="20" />error_captchafield'
@@ -28,15 +28,15 @@ public function test_posted(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->CaptchaField("Captchafield", "captchafield");
 
-        $this->assertFalse($form->isCorrect());
+        static::assertFalse($form->isCorrect());
 
         $t = $form->catchErrors(false);
 
-        $this->assertEquals(
+        static::assertEquals(
             '<span id="error_captchafield" class="error">You did not enter a correct value for this field!</span>',
             $t['captchafield']
         );
diff --git a/tests/uts/formhandler_CheckboxTest.php b/tests/uts/formhandler_CheckboxTest.php
index 631c1de..c354529 100644
--- a/tests/uts/formhandler_CheckboxTest.php
+++ b/tests/uts/formhandler_CheckboxTest.php
@@ -14,50 +14,50 @@ public function test_new_single(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->checkBox("Checkbox", "checkbox");
 
-        $this->assertEmpty($form->getValue("checkbox"));
+        static::assertEmpty($form->getValue("checkbox"));
 
-        $this->assertFormFlushContains($form, ['Checkbox:<input type="checkbox" name="checkbox" id="checkbox_1" value="on" />error_checkbox']);
+        static::assertFormFlushContains($form, ['Checkbox:<input type="checkbox" name="checkbox" id="checkbox_1" value="on" />error_checkbox']);
     }
 
     public function test_new_empty_optionArray(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->checkBox("Checkbox", "checkbox", array());
 
-        $this->assertFormFlushContains($form, ['Checkbox:error_checkbox']);
+        static::assertFormFlushContains($form, ['Checkbox:error_checkbox']);
     }
 
     public function test_new_single_viewmode(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->checkBox("Checkbox", "checkbox");
         $form->setFieldViewMode("checkbox");
 
-        $this->assertFormFlushContains($form, ['Checkbox:error_checkbox']);
+        static::assertFormFlushContains($form, ['Checkbox:error_checkbox']);
     }
 
     public function test_setValue(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->checkBox("Checkbox", "checkbox", $this->aChecks);
 
         $form->setValue("checkbox", "c1,c3,");
-        $this->assertEquals(array("c1", "c3"), $form->getValue("checkbox"));
+        static::assertEquals(array("c1", "c3"), $form->getValue("checkbox"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Checkbox:<input type="checkbox" name="checkbox[]" id="checkbox_1" value="c1" checked="checked" /><label for="checkbox_1" class="noStyle">Check1</label>',
             '<input type="checkbox" name="checkbox[]" id="checkbox_2" value="c2" /><label for="checkbox_2" class="noStyle">Check2</label>',
             '<input type="checkbox" name="checkbox[]" id="checkbox_3" value="c3" checked="checked" /><label for="checkbox_3" class="noStyle">Check3</label>error_checkbox'
@@ -68,12 +68,12 @@ public function test_setMask(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->checkBox("Checkbox", "checkbox", $this->aChecks, null, null, null, "nofield");
         $form->checkBox("Checkbox2", "checkbox2", $this->aChecks, null, null, null, "with a %field%");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Checkbox:<input type="checkbox" name="checkbox[]" id="checkbox_1" value="c1" /><label for="checkbox_1" class="noStyle">Check1</label>nofield',
             '<input type="checkbox" name="checkbox[]" id="checkbox_2" value="c2" /><label for="checkbox_2" class="noStyle">Check2</label>nofield',
             '<input type="checkbox" name="checkbox[]" id="checkbox_3" value="c3" /><label for="checkbox_3" class="noStyle">Check3</label>nofielderror_checkbox',
@@ -87,13 +87,13 @@ public function test_new_array(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->checkBox("Checkbox", "checkbox", $this->aChecks);
 
-        $this->assertEmpty($form->getValue("checkbox"));
+        static::assertEmpty($form->getValue("checkbox"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Checkbox:<input type="checkbox" name="checkbox[]" id="checkbox_1" value="c1" /><label for="checkbox_1" class="noStyle">Check1</label>',
             '<input type="checkbox" name="checkbox[]" id="checkbox_2" value="c2" /><label for="checkbox_2" class="noStyle">Check2</label>',
             '<input type="checkbox" name="checkbox[]" id="checkbox_3" value="c3" /><label for="checkbox_3" class="noStyle">Check3</label>',
@@ -105,13 +105,13 @@ public function test_new_array_useArrayKeyAsValueFalse(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->checkBox("Checkbox", "checkbox", $this->aChecks, null, false);
 
-        $this->assertEmpty($form->getValue("checkbox"));
+        static::assertEmpty($form->getValue("checkbox"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Checkbox:<input type="checkbox" name="checkbox[]" id="checkbox_1" value="Check1" /><label for="checkbox_1" class="noStyle">Check1</label>',
             '<input type="checkbox" name="checkbox[]" id="checkbox_2" value="Check2" /><label for="checkbox_2" class="noStyle">Check2</label>',
             '<input type="checkbox" name="checkbox[]" id="checkbox_3" value="Check3" /><label for="checkbox_3" class="noStyle">Check3</label>',
@@ -123,13 +123,13 @@ public function test_new_array_extra(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->checkBox("Checkbox", "checkbox", $this->aChecks, null, null, 'data-extra="true"');
 
-        $this->assertEmpty($form->getValue("checkbox"));
+        static::assertEmpty($form->getValue("checkbox"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Checkbox:<input type="checkbox" name="checkbox[]" id="checkbox_1" value="c1" data-extra="true" /><label for="checkbox_1" class="noStyle">Check1</label>',
             '<input type="checkbox" name="checkbox[]" id="checkbox_2" value="c2" data-extra="true" /><label for="checkbox_2" class="noStyle">Check2</label>',
             '<input type="checkbox" name="checkbox[]" id="checkbox_3" value="c3" data-extra="true" /><label for="checkbox_3" class="noStyle">Check3</label>',
@@ -141,13 +141,13 @@ public function test_new_array_mask(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->checkBox("Checkbox", "checkbox", $this->aChecks, null, null, null, "%field%ABC");
 
-        $this->assertEmpty($form->getValue("checkbox"));
+        static::assertEmpty($form->getValue("checkbox"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Checkbox:<input type="checkbox" name="checkbox[]" id="checkbox_1" value="c1" /><label for="checkbox_1" class="noStyle">Check1</label>ABC',
             '<input type="checkbox" name="checkbox[]" id="checkbox_2" value="c2" /><label for="checkbox_2" class="noStyle">Check2</label>ABC',
             '<input type="checkbox" name="checkbox[]" id="checkbox_3" value="c3" /><label for="checkbox_3" class="noStyle">Check3</label>ABC',
@@ -162,11 +162,11 @@ public function test_posted_single(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->checkBox("Checkbox", "checkbox");
 
-        $this->assertEquals("on", $form->getValue("checkbox"));
+        static::assertEquals("on", $form->getValue("checkbox"));
     }
 
     public function test_posted_array(): void
@@ -176,11 +176,11 @@ public function test_posted_array(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->checkBox("Checkbox", "checkbox", $this->aChecks);
 
-        $this->assertEquals(["Check1", "Check2"], $form->getValue("checkbox"));
+        static::assertEquals(["Check1", "Check2"], $form->getValue("checkbox"));
     }
 
     public function test_posted_single_fillvalue_byinvalid(): void
@@ -190,14 +190,14 @@ public function test_posted_single_fillvalue_byinvalid(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->checkBox("Checkbox", "checkbox");
 
-        $this->assertEquals("on", $form->getValue("checkbox"));
+        static::assertEquals("on", $form->getValue("checkbox"));
 
         $form->setError("checkbox", "forcedError");
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Checkbox:<input type="checkbox" name="checkbox" id="checkbox_1" value="on" checked="checked" class="error" />error_checkbox',
             '<span id="error_checkbox" class="error">forcedError</span>'
         ]);
@@ -210,11 +210,11 @@ public function test_posted_array_fillvalue_byinvalid(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->checkBox("Checkbox", "checkbox", $this->aChecks);
 
-        $this->assertEquals(["Check1", "Check2"], $form->getValue("checkbox"));
+        static::assertEquals(["Check1", "Check2"], $form->getValue("checkbox"));
     }
 
     public function test_posted_fillvalue_byinvalid(): void
@@ -224,15 +224,15 @@ public function test_posted_fillvalue_byinvalid(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->textField("Textfield", "textfield");
 
-        $this->assertEquals("textvalue", $form->getValue("textfield"));
+        static::assertEquals("textvalue", $form->getValue("textfield"));
 
         $form->setError("textfield", "forcedError");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Textfield:<input type="text" name="textfield" id="textfield" value="textvalue" size="20" class="error" />error_textfield',
             '<span id="error_textfield" class="error">forcedError</span>'
         ]);
@@ -244,15 +244,15 @@ public function test_validator(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->textField("Textfield", "textfield", FH_NOT_EMPTY);
 
-        $this->assertEmpty($form->getValue("textfield"));
+        static::assertEmpty($form->getValue("textfield"));
 
         $t = $form->catchErrors(false);
 
-        $this->assertEquals(
+        static::assertEquals(
             '<span id="error_textfield" class="error">You did not enter a correct value for this field!</span>',
             $t['textfield']
         );
@@ -262,38 +262,38 @@ public function test_new_size(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->textField("Textfield", "textfield", null, 123);
 
-        $this->assertEmpty($form->getValue("textfield"));
+        static::assertEmpty($form->getValue("textfield"));
 
-        $this->assertFormFlushContains($form, ['Textfield:<input type="text" name="textfield" id="textfield" value="" size="123" />error_textfield']);
+        static::assertFormFlushContains($form, ['Textfield:<input type="text" name="textfield" id="textfield" value="" size="123" />error_textfield']);
     }
 
     public function test_new_maxlength(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->textField("Textfield", "textfield", null, null, 123);
 
-        $this->assertEmpty($form->getValue("textfield"));
+        static::assertEmpty($form->getValue("textfield"));
 
-        $this->assertFormFlushContains($form, ['Textfield:<input type="text" name="textfield" id="textfield" value="" size="20" maxlength="123" />error_textfield']);
+        static::assertFormFlushContains($form, ['Textfield:<input type="text" name="textfield" id="textfield" value="" size="20" maxlength="123" />error_textfield']);
     }
 
     public function test_new_extra(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->textField("Textfield", "textfield", null, null, null, 'data-old="123"');
 
-        $this->assertEmpty($form->getValue("textfield"));
+        static::assertEmpty($form->getValue("textfield"));
 
-        $this->assertFormFlushContains($form, ['Textfield:<input type="text" name="textfield" id="textfield" value="" size="20"  data-old="123"']);
+        static::assertFormFlushContains($form, ['Textfield:<input type="text" name="textfield" id="textfield" value="" size="20"  data-old="123"']);
     }
 };
diff --git a/tests/uts/formhandler_ColorPickerTest.php b/tests/uts/formhandler_ColorPickerTest.php
index 0d6f4f0..5a72ab8 100644
--- a/tests/uts/formhandler_ColorPickerTest.php
+++ b/tests/uts/formhandler_ColorPickerTest.php
@@ -8,13 +8,13 @@ public function test_new(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->colorPicker("Colorpicker", "colorpicker");
 
-        $this->assertEmpty($form->getValue("colorpicker"));
+        static::assertEmpty($form->getValue("colorpicker"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'FHTML/js/jscolor/jscolor.js',
             'Colorpicker:<input type="text" name="colorpicker" id="colorpicker" value="" size="20"  class="color" />error_colorpicker'
         ]);
@@ -24,13 +24,13 @@ public function test_viewMode(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->colorPicker("Colorpicker", "colorpicker");
 
         $form->setFieldViewMode("colorpicker");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'FHTML/js/jscolor/jscolor.js',
             'Colorpicker:error_colorpicker'
         ]);
@@ -40,11 +40,11 @@ public function test_extraClass(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->colorPicker("Colorpicker", "colorpicker", null, null, null, "class=\"dummy\"");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'FHTML/js/jscolor/jscolor.js',
             'Colorpicker:<input type="text" name="colorpicker" id="colorpicker" value="" size="20"  class="color dummy" />error_colorpicker'
         ]);
@@ -57,11 +57,11 @@ public function test_posted(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->colorPicker("Colorpicker", "colorpicker");
 
-        $this->assertEquals("FFCC00", $form->getValue("colorpicker"));
+        static::assertEquals("FFCC00", $form->getValue("colorpicker"));
     }
 
     public function test_posted_fillvalue_byinvalid(): void
@@ -71,15 +71,15 @@ public function test_posted_fillvalue_byinvalid(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->colorPicker("Colorpicker", "colorpicker");
 
-        $this->assertEquals("FFCC00", $form->getValue("colorpicker"));
+        static::assertEquals("FFCC00", $form->getValue("colorpicker"));
 
         $form->setError("colorpicker", "forcedError");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Colorpicker:<input type="text" name="colorpicker" id="colorpicker" value="FFCC00" size="20"  class="error color" />error_colorpicker',
             '<span id="error_colorpicker" class="error">forcedError</span>'
         ]);
diff --git a/tests/uts/formhandler_ConstructorTest.php b/tests/uts/formhandler_ConstructorTest.php
index 76c9155..860026d 100644
--- a/tests/uts/formhandler_ConstructorTest.php
+++ b/tests/uts/formhandler_ConstructorTest.php
@@ -13,17 +13,17 @@ public function testStandardFormname_POST(): void
     {
         $form = new FormHandler();
 
-        $this->assertEquals(FH_DEFAULT_FORM_NAME, $form->getFormName());
-        $this->assertFalse($form->isPosted());
-
-        $this->assertEquals(1, $form->getCurrentPage());
-        $this->assertEquals(1, $form->getLastSubmittedPage());
-        $this->assertEquals(1, $form->getPage());
-        $this->assertEquals(FH_DEFAULT_LANGUAGE, $form->getLang());
-        $this->assertEquals(FH_DEFAULT_LANGUAGE, $form->getLanguage());
-        $this->assertEmpty($form->getJavascriptCode());
-        $this->assertTrue($form->isCorrect());
-        $this->assertFalse($form->isViewMode());
+        static::assertEquals(FH_DEFAULT_FORM_NAME, $form->getFormName());
+        static::assertFalse($form->isPosted());
+
+        static::assertEquals(1, $form->getCurrentPage());
+        static::assertEquals(1, $form->getLastSubmittedPage());
+        static::assertEquals(1, $form->getPage());
+        static::assertEquals(FH_DEFAULT_LANGUAGE, $form->getLang());
+        static::assertEquals(FH_DEFAULT_LANGUAGE, $form->getLanguage());
+        static::assertEmpty($form->getJavascriptCode());
+        static::assertTrue($form->isCorrect());
+        static::assertFalse($form->isViewMode());
 
         $aExpected = [
             '<form id="' . FH_DEFAULT_FORM_NAME . '" method="post" action="',
@@ -31,16 +31,16 @@ public function testStandardFormname_POST(): void
             "</ins><table border='0' cellspacing='0' cellpadding='3' >",
             "<p><span style='font-family:tahoma;font-size:10px;color:#B5B5B5;font-weight:normal;'>This form is generated by </span><a href=\"http://www.formhandler.net\" ><span style=\"font-family:Tahoma;font-size:10px;color:#B5B5B5;\"><strong>FormHandler</strong></span></a></p>",
         ];
-        $this->assertFormFlushContains($form, $aExpected);
+        static::assertFormFlushContains($form, $aExpected);
     }
 
     public function testDeviantFormname_POST(): void
     {
         $form = new FormHandler("DeviantFormName");
 
-        $this->assertEquals("DeviantFormName", $form->getFormName());
+        static::assertEquals("DeviantFormName", $form->getFormName());
 
-        $this->assertFormFlushContains($form, '<form id="DeviantFormName" method="post" action="');
+        static::assertFormFlushContains($form, '<form id="DeviantFormName" method="post" action="');
     }
 
     public function testStandardFormname_POST_submit(): void
@@ -49,10 +49,10 @@ public function testStandardFormname_POST_submit(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
-        $this->assertTrue($form->isCorrect());
+        static::assertTrue($form->isPosted());
+        static::assertTrue($form->isCorrect());
 
-        $this->assertEquals("", $form->flush(true));
+        static::assertEquals("", $form->flush(true));
     }
 
     public function testNoExpose(): void
@@ -67,9 +67,9 @@ public function testNoExpose(): void
             "</ins><table border='0' cellspacing='0' cellpadding='3' >"
         ];
 
-        $html = $this->assertFormFlushContains($form, $aExpected);
+        $html = static::assertFormFlushContains($form, $aExpected);
 
-        $this->assertStringNotContainsString("<p><span style='font-family:tahoma;font-size:10px;color:#B5B5B5;font-weight:normal;'>This form is generated by </span><a href=\"http://www.formhandler.net\" ><span style=\"font-family:Tahoma;font-size:10px;color:#B5B5B5;\"><strong>FormHandler</strong></span></a></p>", $html);
+        static::assertStringNotContainsString("<p><span style='font-family:tahoma;font-size:10px;color:#B5B5B5;font-weight:normal;'>This form is generated by </span><a href=\"http://www.formhandler.net\" ><span style=\"font-family:Tahoma;font-size:10px;color:#B5B5B5;\"><strong>FormHandler</strong></span></a></p>", $html);
     }
 
     public function testTableWith100(): void
@@ -78,7 +78,7 @@ public function testTableWith100(): void
 
         $form = new FormHandler();
 
-        $this->assertFormFlushContains($form, "</ins><table border='0' cellspacing='0' cellpadding='3' width='123' >");
+        static::assertFormFlushContains($form, "</ins><table border='0' cellspacing='0' cellpadding='3' width='123' >");
     }
 
     public function testTableBorder1(): void
@@ -87,7 +87,7 @@ public function testTableBorder1(): void
 
         $form = new FormHandler();
 
-        $this->assertFormFlushContains($form, "</ins><table border='99' cellspacing='0' cellpadding='3' >");
+        static::assertFormFlushContains($form, "</ins><table border='99' cellspacing='0' cellpadding='3' >");
     }
 
     public function testTableCellspacing1(): void
@@ -96,7 +96,7 @@ public function testTableCellspacing1(): void
 
         $form = new FormHandler();
 
-        $this->assertFormFlushContains($form, "</ins><table border='0' cellspacing='99' cellpadding='3' >");
+        static::assertFormFlushContains($form, "</ins><table border='0' cellspacing='99' cellpadding='3' >");
     }
 
     public function testTableCellpadding1(): void
@@ -105,14 +105,14 @@ public function testTableCellpadding1(): void
 
         $form = new FormHandler();
 
-        $this->assertFormFlushContains($form, "</ins><table border='0' cellspacing='0' cellpadding='99' >");
+        static::assertFormFlushContains($form, "</ins><table border='0' cellspacing='0' cellpadding='99' >");
     }
 
     public function testNoField(): void
     {
         $form = new FormHandler();
 
-        $this->assertNull($form->getValue("notexist"));
+        static::assertNull($form->getValue("notexist"));
 
         $this->assertTriggertError('Try to get the value of an unknown field "notexist"!', E_USER_WARNING);
     }
@@ -121,11 +121,11 @@ public function testNoName(): void
     {
         // three different versions
         $form = new FormHandler();
-        $this->assertEquals(FH_DEFAULT_FORM_NAME, $form->getName());
+        static::assertEquals(FH_DEFAULT_FORM_NAME, $form->getName());
         $form2 = new FormHandler();
-        $this->assertEquals(FH_DEFAULT_FORM_NAME . "1", $form2->getName());
+        static::assertEquals(FH_DEFAULT_FORM_NAME . "1", $form2->getName());
         $form3 = new FormHandler();
-        $this->assertEquals(FH_DEFAULT_FORM_NAME . "2", $form3->getName());
+        static::assertEquals(FH_DEFAULT_FORM_NAME . "2", $form3->getName());
     }
 
     public function testSetAction(): void
@@ -134,7 +134,7 @@ public function testSetAction(): void
         $form = new FormHandler(null, "action");
 
         $a = $this->getPrivateProperty($form, "_action");
-        $this->assertEquals("action", $a);
+        static::assertEquals("action", $a);
     }
 
     public function testSetActionFromQueryString(): void
@@ -145,7 +145,7 @@ public function testSetActionFromQueryString(): void
         $form = new FormHandler();
 
         $a = $this->getPrivateProperty($form, "_action");
-        $this->assertEquals("phpself.php", $a);
+        static::assertEquals("phpself.php", $a);
 
         $_SERVER['QUERY_STRING'] = "querystring";
         
@@ -153,7 +153,7 @@ public function testSetActionFromQueryString(): void
         $form2 = new FormHandler();
 
         $a = $this->getPrivateProperty($form2, "_action");
-        $this->assertEquals("phpself.php?querystring", $a);
+        static::assertEquals("phpself.php?querystring", $a);
     }
 
     public function testSetExtra(): void
@@ -162,6 +162,6 @@ public function testSetExtra(): void
         $form = new FormHandler(null, null, "extra");
 
         $a = $this->getPrivateProperty($form, "_extra");
-        $this->assertEquals("extra", $a);
+        static::assertEquals("extra", $a);
     }
 }
diff --git a/tests/uts/formhandler_DataHandlingTest.php b/tests/uts/formhandler_DataHandlingTest.php
index 7137ca4..f39650e 100644
--- a/tests/uts/formhandler_DataHandlingTest.php
+++ b/tests/uts/formhandler_DataHandlingTest.php
@@ -19,20 +19,20 @@ public function testGetAsArray(): void
 
         $form->dateField('Date', 'date');
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         list($year, $month, $day) = $form->getAsArray('date');
 
-        $this->assertEquals("2020", $year);
-        $this->assertEquals("3", $month);
-        $this->assertEquals("21", $day);
+        static::assertEquals("2020", $year);
+        static::assertEquals("3", $month);
+        static::assertEquals("21", $day);
     }
 
     public function testGetAsArray_expectedError(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->getAsArray('date'));
+        static::assertFalse($form->getAsArray('date'));
 
         $this->assertTriggertError('The datefield "date" does not exists!', E_USER_NOTICE);
     }
@@ -46,10 +46,10 @@ public function testGetValue(): void
 
         $form->textField("Name", "name");
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
-        $this->assertEquals("Text", $form->getValue("name"));
-        $this->assertEquals("Text", $form->value("name"));
+        static::assertEquals("Text", $form->getValue("name"));
+        static::assertEquals("Text", $form->value("name"));
     }
 
     public function testSetValue(): void
@@ -59,11 +59,11 @@ public function testSetValue(): void
         $form->textField("Name", "name", FH_STRING);
         $form->setValue("name", "defaultValue");
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $expected  = 'value="defaultValue"';
 
-        $this->assertStringContainsString($expected, $form->flush(true));
+        static::assertStringContainsString($expected, $form->flush(true));
     }
 
     public function testAddValue(): void
@@ -75,16 +75,16 @@ public function testAddValue(): void
 
         $form->textField("Name", "name", FH_STRING);
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
-        $this->assertEquals("Text", $form->getValue("name"));
+        static::assertEquals("Text", $form->getValue("name"));
 
         $form->addValue("name", "Code");
 
         $form->onCorrect("doRun_ReturnDataName");
 
         $expected  = "Code";
-        $this->assertStringContainsString($expected, $form->flush(true));
+        static::assertStringContainsString($expected, $form->flush(true));
     }
 
     public function testOnCorrect(): void
@@ -99,7 +99,7 @@ public function testOnCorrect(): void
         $form->onCorrect("doRun_ReturnDataName");
 
         $expected  = $_POST['name'];
-        $this->assertEquals($expected, $form->flush(true));
+        static::assertEquals($expected, $form->flush(true));
     }
 
     public function testOnCorrect_Class(): void
@@ -120,7 +120,7 @@ public function testOnCorrect_Class(): void
         );
 
         $expected  = $_POST['name'];
-        $this->assertEquals($expected, $form->flush(true));
+        static::assertEquals($expected, $form->flush(true));
     }
 
     public function testOnCorrect_Validation_false(): void
@@ -136,7 +136,7 @@ public function testOnCorrect_Validation_false(): void
 
         $expected  = '<span id="error_name" class="error">Your name has to be at least 3 characters!</span>';
 
-        $this->assertStringContainsString($expected, $form->flush(true));
+        static::assertStringContainsString($expected, $form->flush(true));
     }
 
     public function testOnCorrect_Validation_true(): void
@@ -151,7 +151,7 @@ public function testOnCorrect_Validation_true(): void
         $form->onCorrect("doRun_testOnCorrect_Validation");
 
         $expected  = $_POST['name'];
-        $this->assertEquals($expected, $form->flush(true));
+        static::assertEquals($expected, $form->flush(true));
     }
 
     public function testSetError(): void
@@ -163,7 +163,7 @@ public function testSetError(): void
         $form->setError("name", "This is an error");
 
         $expected  = '<span id="error_name" class="error">This is an error</span>';
-        $this->assertStringContainsString($expected, $form->flush(true));
+        static::assertStringContainsString($expected, $form->flush(true));
     }
 }
 
diff --git a/tests/uts/formhandler_DateFieldTest.php b/tests/uts/formhandler_DateFieldTest.php
index 03cb308..2f2aafc 100644
--- a/tests/uts/formhandler_DateFieldTest.php
+++ b/tests/uts/formhandler_DateFieldTest.php
@@ -50,7 +50,7 @@ public function test_new(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->dateField("Datefield", "datefield");
 
@@ -65,14 +65,14 @@ public function test_new(): void
         $aExpected = array_merge($aExpected, $this->getYears($startYear, $endYear, date('Y')));
         $aExpected[] = '</select> error_datefield';
 
-        $this->assertFormFlushContains($form, $aExpected);
+        static::assertFormFlushContains($form, $aExpected);
     }
 
     public function test_new_required(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->dateField("Datefield", "datefield", null, true);
 
@@ -87,8 +87,8 @@ public function test_new_required(): void
         $aExpected = array_merge($aExpected, $this->getYears($startYear, $endYear, date('Y')));
         $aExpected[] = '</select> error_datefield';
 
-        $t = $this->assertFormFlushContains($form, $aExpected);
-        $this->assertFalse(strpos($t, '<option  value="" ></option>'));
+        $t = static::assertFormFlushContains($form, $aExpected);
+        static::assertFalse(strpos($t, '<option  value="" ></option>'));
     }
 
     public function test_new_no_default(): void
@@ -96,7 +96,7 @@ public function test_new_no_default(): void
         define('FH_DATEFIELD_SET_CUR_DATE', false);
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->dateField("Datefield", "datefield");
 
@@ -111,14 +111,14 @@ public function test_new_no_default(): void
         $aExpected = array_merge($aExpected, $this->getYears($startYear, $endYear));
         $aExpected[] = '</select> error_datefield';
 
-        $this->assertFormFlushContains($form, $aExpected);
+        static::assertFormFlushContains($form, $aExpected);
     }
 
     public function test_interval(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->dateField("Datefield", "datefield", null, null, null, '20:20');
 
@@ -133,7 +133,7 @@ public function test_interval(): void
         $aExpected = array_merge($aExpected, $this->getYears($startYear, $endYear, date('Y')));
         $aExpected[] = '</select> error_datefield';
 
-        $this->assertFormFlushContains($form, $aExpected);
+        static::assertFormFlushContains($form, $aExpected);
     }
 
     public function test_posted(): void
@@ -154,22 +154,22 @@ public function test_posted(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->dateField("Datefield", "datefield");
         $form->dateField("Datefield2", "datefield2", null, null, "d.m.y");
         $form->dateField("Datefield3", "datefield3", null, null, "y/m/d");
         $form->dateField("Datefield4", "datefield4", null, null, "D-M-Y");
 
-        $this->assertEquals("03-04-2018", $form->getValue("datefield"));
-        $this->assertEquals("03.04.2018", $form->getValue("datefield2"));
-        $this->assertEquals("2018/04/03", $form->getValue("datefield3"));
-        $this->assertEquals("03-04-2018", $form->getValue("datefield4"));
+        static::assertEquals("03-04-2018", $form->getValue("datefield"));
+        static::assertEquals("03.04.2018", $form->getValue("datefield2"));
+        static::assertEquals("2018/04/03", $form->getValue("datefield3"));
+        static::assertEquals("03-04-2018", $form->getValue("datefield4"));
 
-        $this->assertEquals([2018, 4, 3], $form->getAsArray("datefield"));
-        $this->assertEquals([2018, 4, 3], $form->getAsArray("datefield2"));
-        $this->assertEquals([2018, 4, 3], $form->getAsArray("datefield3"));
-        $this->assertEquals([2018, 4, 3], $form->getAsArray("datefield4"));
+        static::assertEquals([2018, 4, 3], $form->getAsArray("datefield"));
+        static::assertEquals([2018, 4, 3], $form->getAsArray("datefield2"));
+        static::assertEquals([2018, 4, 3], $form->getAsArray("datefield3"));
+        static::assertEquals([2018, 4, 3], $form->getAsArray("datefield4"));
     }
 
     public function different_masks(): array
@@ -203,18 +203,18 @@ public function test_getValue($different_masks): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->dateField("Datefield", "datefield", null, null, $different_masks[0]);
 
-         $this->assertEquals($different_masks[1], $form->getValue("datefield"));
+         static::assertEquals($different_masks[1], $form->getValue("datefield"));
     }
 
     public function test_new_mask1(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->dateField("Datefield", "datefield", null, null, "y-m-d");
 
@@ -229,14 +229,14 @@ public function test_new_mask1(): void
         $aExpected = array_merge($aExpected, $this->getDays(31, date('d')));
         $aExpected[] = '</select> error_datefield';
 
-        $this->assertFormFlushContains($form, $aExpected);
+        static::assertFormFlushContains($form, $aExpected);
     }
 
     public function test_new_mask2(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->dateField("Datefield", "datefield", null, null, "d.m.y");
 
@@ -251,7 +251,7 @@ public function test_new_mask2(): void
         $aExpected = array_merge($aExpected, $this->getYears($startYear, $endYear, date('Y')));
         $aExpected[] = '</select> error_datefield';
 
-        $this->assertFormFlushContains($form, $aExpected);
+        static::assertFormFlushContains($form, $aExpected);
     }
 
     public function test_new_editfields(): void
@@ -259,12 +259,12 @@ public function test_new_editfields(): void
         define('FH_DATEFIELD_SET_CUR_DATE', false);
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->dateField("Datefield", "datefield", null, null, "D-M-Y");
         $form->dateField("Datefield2", "datefield2", null, null, "Y.M-D");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Datefield: <input type="text" name="datefield_day" id="datefield_day" value="" size="2" maxlength="2" /> - <input type="text" name="datefield_month" id="datefield_month" value="" size="2" maxlength="2" /> - <input type="text" name="datefield_year" id="datefield_year" value="" size="4" maxlength="4" /> error_datefield',
             'Datefield2: <input type="text" name="datefield2_year" id="datefield2_year" value="" size="4" maxlength="4" /> . <input type="text" name="datefield2_month" id="datefield2_month" value="" size="2" maxlength="2" /> - <input type="text" name="datefield2_day" id="datefield2_day" value="" size="2" maxlength="2" /> error_datefield2'
         ]);
@@ -279,15 +279,15 @@ public function test_posted_editfields_fillvalue_byinvalid(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->dateField("Datefield", "datefield", null, null, "D-M-Y");
 
-        $this->assertEquals("03-04-2018", $form->getValue("datefield"));
+        static::assertEquals("03-04-2018", $form->getValue("datefield"));
 
         $form->setError("datefield", "forcedError");
 
-        $this->assertFormFlushContains($form, 'Datefield: <input type="text" name="datefield_day" id="datefield_day" value="03" size="2" maxlength="2" class="error" />' .
+        static::assertFormFlushContains($form, 'Datefield: <input type="text" name="datefield_day" id="datefield_day" value="03" size="2" maxlength="2" class="error" />' .
             ' - <input type="text" name="datefield_month" id="datefield_month" value="04" size="2" maxlength="2" class="error" />' .
             ' - <input type="text" name="datefield_year" id="datefield_year" value="2018" size="4" maxlength="4" class="error" />' .
             ' error_datefield<span id="error_datefield" class="error">forcedError');
@@ -302,13 +302,13 @@ public function test_posted_editfields_invalidDate(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->dateField("Datefield", "datefield", null, null, "D-M-Y");
 
-        $this->assertEquals("43-04-2018", $form->getValue("datefield"));
+        static::assertEquals("43-04-2018", $form->getValue("datefield"));
 
-        $this->assertFormFlushContains($form, 'Datefield: <input type="text" name="datefield_day" id="datefield_day" value="43" size="2" maxlength="2" class="error" />' .
+        static::assertFormFlushContains($form, 'Datefield: <input type="text" name="datefield_day" id="datefield_day" value="43" size="2" maxlength="2" class="error" />' .
             ' - <input type="text" name="datefield_month" id="datefield_month" value="04" size="2" maxlength="2" class="error" />' .
             ' - <input type="text" name="datefield_year" id="datefield_year" value="2018" size="4" maxlength="4" class="error" />' .
             ' error_datefield<span id="error_datefield" class="error">The given date is not valid!</span>'
@@ -324,11 +324,11 @@ public function test_posted_editfields_invalidDay(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->dateField("Datefield", "datefield", null, null, "D-M-Y");
 
-        $this->assertFormFlushContains($form, 'Datefield: <input type="text" name="datefield_day" id="datefield_day" value="A" size="2" maxlength="2" class="error" />' .
+        static::assertFormFlushContains($form, 'Datefield: <input type="text" name="datefield_day" id="datefield_day" value="A" size="2" maxlength="2" class="error" />' .
             ' - <input type="text" name="datefield_month" id="datefield_month" value="04" size="2" maxlength="2" class="error" />' .
             ' - <input type="text" name="datefield_year" id="datefield_year" value="2018" size="4" maxlength="4" class="error" />' .
             ' error_datefield<span id="error_datefield" class="error"><span id="error_datefield_day" class="error">You did not enter a correct value for this field!</span></span>'
@@ -344,11 +344,11 @@ public function test_posted_editfields_invalidMonth(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->dateField("Datefield", "datefield", null, null, "D-M-Y");
 
-        $this->assertFormFlushContains($form, 'Datefield: <input type="text" name="datefield_day" id="datefield_day" value="01" size="2" maxlength="2" class="error" />' .
+        static::assertFormFlushContains($form, 'Datefield: <input type="text" name="datefield_day" id="datefield_day" value="01" size="2" maxlength="2" class="error" />' .
             ' - <input type="text" name="datefield_month" id="datefield_month" value="A" size="2" maxlength="2" class="error" />' .
             ' - <input type="text" name="datefield_year" id="datefield_year" value="2018" size="4" maxlength="4" class="error" />' .
             ' error_datefield<span id="error_datefield" class="error"><span id="error_datefield_month" class="error">You did not enter a correct value for this field!</span>'
@@ -364,11 +364,11 @@ public function test_posted_editfields_invalidYear1(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->dateField("Datefield", "datefield", null, null, "D-M-Y");
 
-        $this->assertFormFlushContains($form, 'Datefield: <input type="text" name="datefield_day" id="datefield_day" value="01" size="2" maxlength="2" class="error" />' .
+        static::assertFormFlushContains($form, 'Datefield: <input type="text" name="datefield_day" id="datefield_day" value="01" size="2" maxlength="2" class="error" />' .
             ' - <input type="text" name="datefield_month" id="datefield_month" value="04" size="2" maxlength="2" class="error" />' .
             ' - <input type="text" name="datefield_year" id="datefield_year" value="A" size="4" maxlength="4" class="error" />' .
             ' error_datefield<span id="error_datefield" class="error"><span id="error_datefield_year" class="error">You did not enter a correct value for this field!</span></span>'
@@ -384,11 +384,11 @@ public function test_posted_editfields_invalidYear2(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->dateField("Datefield", "datefield", null, null, "D-M-Y");
 
-        $this->assertFormFlushContains($form, 'Datefield: <input type="text" name="datefield_day" id="datefield_day" value="01" size="2" maxlength="2" class="error" />' .
+        static::assertFormFlushContains($form, 'Datefield: <input type="text" name="datefield_day" id="datefield_day" value="01" size="2" maxlength="2" class="error" />' .
             ' - <input type="text" name="datefield_month" id="datefield_month" value="04" size="2" maxlength="2" class="error" />' .
             ' - <input type="text" name="datefield_year" id="datefield_year" value="123" size="4" maxlength="4" class="error" />' .
             ' error_datefield<span id="error_datefield" class="error">The given date is not valid!</span>'
@@ -399,7 +399,7 @@ public function test_new_extra(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->dateField("Datefield", "datefield", null, null, null, null, 'data-old="123"');
 
@@ -414,6 +414,6 @@ public function test_new_extra(): void
         $aExpected = array_merge($aExpected, $this->getYears($startYear, $endYear, date('Y')));
         $aExpected[] = '</select> error_datefield';
 
-        $this->assertFormFlushContains($form, $aExpected);
+        static::assertFormFlushContains($form, $aExpected);
     }
 };
diff --git a/tests/uts/formhandler_DateTextFieldTest.php b/tests/uts/formhandler_DateTextFieldTest.php
index 3a96d55..1f01377 100644
--- a/tests/uts/formhandler_DateTextFieldTest.php
+++ b/tests/uts/formhandler_DateTextFieldTest.php
@@ -8,13 +8,13 @@ public function test_new(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->dateTextField("DateTextField", "datetextfield");
 
-        $this->assertEmpty($form->getValue("datetextfield"));
+        static::assertEmpty($form->getValue("datetextfield"));
 
-        $this->assertFormFlushContains($form, ['DateTextField:<input type="text" name="datetextfield" id="datetextfield" value="" size="20" />error_datetextfield']);
+        static::assertFormFlushContains($form, ['DateTextField:<input type="text" name="datetextfield" id="datetextfield" value="" size="20" />error_datetextfield']);
     }
 
     public function test_posted(): void
@@ -27,28 +27,28 @@ public function test_posted(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->dateTextField("Datetextfield", "datetextfield");
         $form->dateTextField("Datetextfield2", "datetextfield2");
         $form->dateTextField("Datetextfield3", "datetextfield3", null, "d.m.Y");
         $form->dateTextField("Datetextfield4", "datetextfield4", null, null, true);
 
-        $this->assertEquals("14-04-2020", $form->getValue("datetextfield"));
-        $this->assertEquals("14.04.2020", $form->getValue("datetextfield2"));
-        $this->assertEquals("14.04.2020", $form->getValue("datetextfield3"));
-        $this->assertEquals("14-04-2020", $form->getValue("datetextfield4"));  // already parsed into correct presentation!
+        static::assertEquals("14-04-2020", $form->getValue("datetextfield"));
+        static::assertEquals("14.04.2020", $form->getValue("datetextfield2"));
+        static::assertEquals("14.04.2020", $form->getValue("datetextfield3"));
+        static::assertEquals("14-04-2020", $form->getValue("datetextfield4"));  // already parsed into correct presentation!
 
-        $this->assertEquals([2020, 4, 14], $form->getAsArray("datetextfield"));
-        $this->assertNull($form->getAsArray("datetextfield2"));
+        static::assertEquals([2020, 4, 14], $form->getAsArray("datetextfield"));
+        static::assertNull($form->getAsArray("datetextfield2"));
         $this->assertTriggertError("Value is not a valid date [14.04.2020]", E_USER_ERROR);
-        $this->assertEquals([2020, 4, 14], $form->getAsArray("datetextfield3"));
-        $this->assertEquals([2020, 4, 14], $form->getAsArray("datetextfield4"));
+        static::assertEquals([2020, 4, 14], $form->getAsArray("datetextfield3"));
+        static::assertEquals([2020, 4, 14], $form->getAsArray("datetextfield4"));
 
         $e = $form->catchErrors();
 
-        $this->assertEquals(1, sizeof($e));
-        $this->assertEquals('<span id="error_datetextfield2" class="error">You did not enter a correct value for this field!</span>', $e['datetextfield2']);
+        static::assertEquals(1, sizeof($e));
+        static::assertEquals('<span id="error_datetextfield2" class="error">You did not enter a correct value for this field!</span>', $e['datetextfield2']);
     }
 
     public function test_posted_fillvalue_byinvalid(): void
@@ -58,15 +58,15 @@ public function test_posted_fillvalue_byinvalid(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->dateTextField("DateTextField", "datetextfield");
 
-        $this->assertEquals("14-04-2020", $form->getValue("datetextfield"));
+        static::assertEquals("14-04-2020", $form->getValue("datetextfield"));
 
         $form->setError("datetextfield", "forcedError");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'DateTextField:<input type="text" name="datetextfield" id="datetextfield" value="14-04-2020" size="20" class="error" />error_datetextfield',
             '<span id="error_datetextfield" class="error">forcedError</span>'
         ]);
@@ -78,15 +78,15 @@ public function test_validator(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->dateTextField("DateTextField", "datetextfield", FH_NOT_EMPTY);
 
-        $this->assertEmpty($form->getValue("datetextfield"));
+        static::assertEmpty($form->getValue("datetextfield"));
 
         $t = $form->catchErrors(false);
 
-        $this->assertEquals(
+        static::assertEquals(
             '<span id="error_datetextfield" class="error">You did not enter a correct value for this field!</span>',
             $t['datetextfield']
         );
@@ -96,13 +96,13 @@ public function test_new_extra(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->dateTextField("DateTextField", "datetextfield", null, null, null, 'data-old="123"');
 
-        $this->assertEmpty($form->getValue("datetextfield"));
+        static::assertEmpty($form->getValue("datetextfield"));
 
-        $this->assertFormFlushContains($form, ['DateTextField:<input type="text" name="datetextfield" id="datetextfield" value="" size="20"  data-old="123"']);
+        static::assertFormFlushContains($form, ['DateTextField:<input type="text" name="datetextfield" id="datetextfield" value="" size="20"  data-old="123"']);
     }
 
     public function dataTestGetAsArray(): array
@@ -146,13 +146,13 @@ public function testGetAsArray($dataTestGetAsArray): void
 
         $form->dateTextField("DateTextField", "datetextfield", null, $dataTestGetAsArray['mask']);
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         list($year, $month, $day) = $form->getAsArray('datetextfield');
 
-        $this->assertEquals($dataTestGetAsArray['result']['year'], $year);
-        $this->assertEquals($dataTestGetAsArray['result']['month'], $month);
-        $this->assertEquals($dataTestGetAsArray['result']['day'], $day);
+        static::assertEquals($dataTestGetAsArray['result']['year'], $year);
+        static::assertEquals($dataTestGetAsArray['result']['month'], $month);
+        static::assertEquals($dataTestGetAsArray['result']['day'], $day);
     }
 
     /**
@@ -169,26 +169,26 @@ public function testParseOtherRepresentaions($dataTestGetAsArray): void
         $form->dateTextField("DateTextField", "datetextfield", null, null, false);
         $form->dateTextField("DateTextField2", "datetextfield2", null, null, true);
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         if ($dataTestGetAsArray['mask'] != FH_DATETEXTFIELD_DEFAULT_DISPLAY)
         {
-            $this->assertNull($form->getAsArray('datetextfield'));
+            static::assertNull($form->getAsArray('datetextfield'));
             $this->assertTriggertError("Value is not a valid date [" . $dataTestGetAsArray['value'] . "]", E_USER_ERROR);
         }
         else
         {
             list($year, $month, $day) = $form->getAsArray('datetextfield');
 
-            $this->assertEquals($dataTestGetAsArray['result']['year'], $year);
-            $this->assertEquals($dataTestGetAsArray['result']['month'], $month);
-            $this->assertEquals($dataTestGetAsArray['result']['day'], $day);
+            static::assertEquals($dataTestGetAsArray['result']['year'], $year);
+            static::assertEquals($dataTestGetAsArray['result']['month'], $month);
+            static::assertEquals($dataTestGetAsArray['result']['day'], $day);
 
             list($year2, $month2, $day2) = $form->getAsArray('datetextfield2');
 
-            $this->assertEquals($dataTestGetAsArray['result']['year'], $year2);
-            $this->assertEquals($dataTestGetAsArray['result']['month'], $month2);
-            $this->assertEquals($dataTestGetAsArray['result']['day'], $day2);
+            static::assertEquals($dataTestGetAsArray['result']['year'], $year2);
+            static::assertEquals($dataTestGetAsArray['result']['month'], $month2);
+            static::assertEquals($dataTestGetAsArray['result']['day'], $day2);
         }
     }
 };
diff --git a/tests/uts/formhandler_EditorTest.php b/tests/uts/formhandler_EditorTest.php
index 591752e..97dee23 100644
--- a/tests/uts/formhandler_EditorTest.php
+++ b/tests/uts/formhandler_EditorTest.php
@@ -8,13 +8,13 @@ public function test_new(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->editor("Editor", "editor");
 
-        $this->assertEmpty($form->getValue("editor"));
+        static::assertEmpty($form->getValue("editor"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'FHTML/ckeditor/ckeditor.js',
             'Editor:<textarea name="editor" id="editor" cols="40" rows="7"></textarea>error_editor',
             'CKEDITOR.replace( \'editor\', {"toolbar":"Default"',
@@ -29,11 +29,11 @@ public function test_posted(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->editor("Editor", "editor");
 
-        $this->assertEquals("textvalue", $form->getValue("editor"));
+        static::assertEquals("textvalue", $form->getValue("editor"));
     }
 
     public function test_posted_fillvalue_byinvalid(): void
@@ -43,15 +43,15 @@ public function test_posted_fillvalue_byinvalid(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->editor("Editor", "editor");
 
-        $this->assertEquals("textvalue", $form->getValue("editor"));
+        static::assertEquals("textvalue", $form->getValue("editor"));
 
         $form->setError("editor", "forcedError");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'FHTML/ckeditor/ckeditor.js',
             'Editor:<textarea class="error" name="editor" id="editor" cols="40" rows="7">textvalue</textarea>error_editor',
             'CKEDITOR.replace( \'editor\', {"toolbar":"Default"'
@@ -64,7 +64,7 @@ public function test_path(): void
 
         $form->editor("Editor", "editor", null, "thisisthepath");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'FHTML/ckeditor/ckeditor.js',
             'Editor:<textarea name="editor" id="editor" cols="40" rows="7"></textarea>error_editor',
             'CKEDITOR.replace( \'editor\', {"toolbar":"Default"',
@@ -79,7 +79,7 @@ public function test_toolbar(): void
 
         $form->editor("Editor", "editor", null, null, "thetoolbar");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'FHTML/ckeditor/ckeditor.js',
             'Editor:<textarea name="editor" id="editor" cols="40" rows="7"></textarea>error_editor',
             'CKEDITOR.replace( \'editor\', {"toolbar":"thetoolbar"',
@@ -93,7 +93,7 @@ public function test_skin(): void
 
         $form->editor("Editor", "editor", null, null, null, "theskin");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'FHTML/ckeditor/ckeditor.js',
             'Editor:<textarea name="editor" id="editor" cols="40" rows="7"></textarea>error_editor',
             'CKEDITOR.replace( \'editor\', {"toolbar":"Default"',
@@ -107,7 +107,7 @@ public function test_size(): void
 
         $form->editor("Editor", "editor", null, null, null, null, 123, 456);
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'FHTML/ckeditor/ckeditor.js',
             'Editor:<textarea name="editor" id="editor" cols="40" rows="7"></textarea>error_editor',
             'CKEDITOR.replace( \'editor\', {"toolbar":"Default"',
@@ -121,7 +121,7 @@ public function test_config(): void
 
         $form->editor("Editor", "editor", null, null, null, null, null, null, ["theconfig" => "vals"]);
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'FHTML/ckeditor/ckeditor.js',
             'Editor:<textarea name="editor" id="editor" cols="40" rows="7"></textarea>error_editor',
             'CKEDITOR.replace( \'editor\', {"toolbar":"Default"',
diff --git a/tests/uts/formhandler_HiddenFieldTest.php b/tests/uts/formhandler_HiddenFieldTest.php
index 1e027f4..6f53978 100644
--- a/tests/uts/formhandler_HiddenFieldTest.php
+++ b/tests/uts/formhandler_HiddenFieldTest.php
@@ -8,13 +8,13 @@ public function test_new(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->hiddenField("hiddenfield", "thevalue");
 
-        $this->assertEquals("thevalue", $form->getValue("hiddenfield"));
+        static::assertEquals("thevalue", $form->getValue("hiddenfield"));
 
-        $this->assertFormFlushContains($form, ['<input type="hidden" name="hiddenfield" id="hiddenfield" value="thevalue" />']);
+        static::assertFormFlushContains($form, ['<input type="hidden" name="hiddenfield" id="hiddenfield" value="thevalue" />']);
     }
 
     public function test_posted(): void
@@ -24,11 +24,11 @@ public function test_posted(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->hiddenField("hiddenfield");
 
-        $this->assertEquals("hiddenvalue", $form->getValue("hiddenfield"));
+        static::assertEquals("hiddenvalue", $form->getValue("hiddenfield"));
     }
 
     public function test_posted_fillvalue_byinvalid(): void
@@ -38,15 +38,15 @@ public function test_posted_fillvalue_byinvalid(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->hiddenField("hiddenfield");
 
-        $this->assertEquals("hiddenvalue", $form->getValue("hiddenfield"));
+        static::assertEquals("hiddenvalue", $form->getValue("hiddenfield"));
 
         $form->setError("hiddenfield", "forcedError");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             '<input type="hidden" name="hiddenfield" id="hiddenfield" value="hiddenvalue" />',
             '<span id="error_hiddenfield" class="error">forcedError</span>'
         ]);
@@ -58,15 +58,15 @@ public function test_validator(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->hiddenField("hiddenfield", "", FH_NOT_EMPTY);
 
-        $this->assertEmpty($form->getValue("hiddenfield"));
+        static::assertEmpty($form->getValue("hiddenfield"));
 
         $t = $form->catchErrors(false);
 
-        $this->assertEquals(
+        static::assertEquals(
             '<span id="error_hiddenfield" class="error">You did not enter a correct value for this field!</span>',
             $t['hiddenfield']
         );
@@ -76,12 +76,12 @@ public function test_new_extra(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->hiddenField("hiddenfield", "", null, 'data-old="123"');
 
-        $this->assertEmpty($form->getValue("hiddenfield"));
+        static::assertEmpty($form->getValue("hiddenfield"));
 
-        $this->assertFormFlushContains($form, ['<input type="hidden" name="hiddenfield" id="hiddenfield" value="" data-old="123" />']);
+        static::assertFormFlushContains($form, ['<input type="hidden" name="hiddenfield" id="hiddenfield" value="" data-old="123" />']);
     }
 };
diff --git a/tests/uts/formhandler_ListFieldTest.php b/tests/uts/formhandler_ListFieldTest.php
index 386922e..c66c755 100644
--- a/tests/uts/formhandler_ListFieldTest.php
+++ b/tests/uts/formhandler_ListFieldTest.php
@@ -20,13 +20,13 @@ public function test_new_horizontal(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->listField("Listfield", "listfield", $this->aElements);
 
-        $this->assertEmpty($form->getValue("listfield"));
+        static::assertEmpty($form->getValue("listfield"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Listfield:<input type="hidden" name="listfield" id="listfield" value="" />',
             'SelectedAvailable',
             '<select name="listfield_ListOn[]" id="listfield_ListOn" size="4" multiple="multiple"  ondblclick="changeValue(\'listfield\', false)">',
@@ -45,13 +45,13 @@ public function test_new_vertical(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->listField("Listfield", "listfield", $this->aElements, null, null, null, null, null, null, true);
 
-        $this->assertEmpty($form->getValue("listfield"));
+        static::assertEmpty($form->getValue("listfield"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Listfield:<input type="hidden" name="listfield" id="listfield" value="" />',
             'Available',
             '<select name="listfield_ListOff[]" id="listfield_ListOff" size="4" multiple="multiple"  ondblclick="changeValue(\'listfield\', true)">',
@@ -73,11 +73,11 @@ public function test_posted(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->listField("Listfield", "listfield", $this->aElements);
 
-        $this->assertEquals(['2', '3'], $form->getValue("listfield"));
+        static::assertEquals(['2', '3'], $form->getValue("listfield"));
     }
 
     public function test_posted_empty(): void
@@ -86,11 +86,11 @@ public function test_posted_empty(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->listField("Listfield", "listfield", $this->aElements);
 
-        $this->assertEquals([], $form->getValue("listfield"));
+        static::assertEquals([], $form->getValue("listfield"));
     }
 
     public function test_posted_useArrayKeyAsValueFalse(): void
@@ -100,11 +100,11 @@ public function test_posted_useArrayKeyAsValueFalse(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->listField("Listfield", "listfield", $this->aElements, null, false);
 
-        $this->assertEquals(['elem2', 'elem3'], $form->getValue("listfield"));
+        static::assertEquals(['elem2', 'elem3'], $form->getValue("listfield"));
     }
 
     public function test_posted_fillvalue_byinvalid_horizontal(): void
@@ -114,15 +114,15 @@ public function test_posted_fillvalue_byinvalid_horizontal(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->listField("Listfield", "listfield", $this->aElements);
 
-        $this->assertEquals(['2', '3'], $form->getValue("listfield"));
+        static::assertEquals(['2', '3'], $form->getValue("listfield"));
 
         $form->setError("listfield", "forcedError");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Listfield:<input type="hidden" name="listfield" id="listfield" value="2,3" />',
             'SelectedAvailable',
             '<select class="error" name="listfield_ListOn[]" id="listfield_ListOn" size="4" multiple="multiple"  ondblclick="changeValue(\'listfield\', false)">',
@@ -144,15 +144,15 @@ public function test_posted_fillvalue_byinvalid_vertical(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->listField("Listfield", "listfield", $this->aElements, null, null, null, null, null, null, true);
 
-        $this->assertEquals(['2', '3'], $form->getValue("listfield"));
+        static::assertEquals(['2', '3'], $form->getValue("listfield"));
 
         $form->setError("listfield", "forcedError");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Listfield:<input type="hidden" name="listfield" id="listfield" value="2,3" />',
             'Available',
             '<select class="error" name="listfield_ListOff[]" id="listfield_ListOff" size="4" multiple="multiple"  ondblclick="changeValue(\'listfield\', true)">',
@@ -173,15 +173,15 @@ public function test_validator(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->listField("Listfield", "listfield", $this->aElements, FH_NOT_EMPTY);
 
-        $this->assertEmpty($form->getValue("listfield"));
+        static::assertEmpty($form->getValue("listfield"));
 
         $t = $form->catchErrors(false);
 
-        $this->assertEquals(
+        static::assertEquals(
             '<span id="error_listfield" class="error">You did not enter a correct value for this field!</span>',
             $t['listfield']
         );
@@ -191,13 +191,13 @@ public function test_new_horizontal_useArrayKeyAsValueFalse(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->listField("Listfield", "listfield", $this->aElements, null, false);
 
-        $this->assertEmpty($form->getValue("listfield"));
+        static::assertEmpty($form->getValue("listfield"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Listfield:<input type="hidden" name="listfield" id="listfield" value="" />',
             'SelectedAvailable',
             '<select name="listfield_ListOn[]" id="listfield_ListOn" size="4" multiple="multiple"  ondblclick="changeValue(\'listfield\', false)">',
@@ -216,13 +216,13 @@ public function test_new_vertical_useArrayKeyAsValueFalse(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->listField("Listfield", "listfield", $this->aElements, null, false, null, null, null, null, true);
 
-        $this->assertEmpty($form->getValue("listfield"));
+        static::assertEmpty($form->getValue("listfield"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Listfield:<input type="hidden" name="listfield" id="listfield" value="" />',
             'Available',
             '<select name="listfield_ListOff[]" id="listfield_ListOff" size="4" multiple="multiple"  ondblclick="changeValue(\'listfield\', true)">',
@@ -244,15 +244,15 @@ public function test_posted_fillvalue_byinvalid_horizontal_useArrayKeyAsValueFal
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->listField("Listfield", "listfield", $this->aElements, null, false);
 
-        $this->assertEquals(['elem2', 'elem3'], $form->getValue("listfield"));
+        static::assertEquals(['elem2', 'elem3'], $form->getValue("listfield"));
 
         $form->setError("listfield", "forcedError");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Listfield:<input type="hidden" name="listfield" id="listfield" value="elem2,elem3" />',
             'SelectedAvailable',
             '<select class="error" name="listfield_ListOn[]" id="listfield_ListOn" size="4" multiple="multiple"  ondblclick="changeValue(\'listfield\', false)">',
@@ -274,15 +274,15 @@ public function test_posted_fillvalue_byinvalid_vertical_useArrayKeyAsValueFalse
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->listField("Listfield", "listfield", $this->aElements, null, false, null, null, null, null, true);
 
-        $this->assertEquals(['elem2', 'elem3'], $form->getValue("listfield"));
+        static::assertEquals(['elem2', 'elem3'], $form->getValue("listfield"));
 
         $form->setError("listfield", "forcedError");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Listfield:<input type="hidden" name="listfield" id="listfield" value="elem2,elem3" />',
             'Available',
             '<select class="error" name="listfield_ListOff[]" id="listfield_ListOff" size="4" multiple="multiple"  ondblclick="changeValue(\'listfield\', true)">',
@@ -301,12 +301,12 @@ public function test_new_offtitle_ontitle(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->listField("ListfieldV", "listfieldV", $this->aElements, null, null, "OnTitleV", "OffTitleV");
         $form->listField("ListfieldH", "listfieldH", $this->aElements, null, null, "OnTitleH", "OffTitleH", null, null, false);
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Select an item to move to the OffTitleV box or double click to move all items',
             'Select an item to move to the OnTitleV box or double click to move all',
             'Select an item to move to the OffTitleH box or double click to move all items',
@@ -318,12 +318,12 @@ public function test_new_size(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->listField("ListfieldV", "listfieldV", $this->aElements, null, null, null, null, 123);
         $form->listField("ListfieldH", "listfieldH", $this->aElements, null, null, null, null, 123, null, false);
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'id="listfieldV_ListOn" size="123"',
             'id="listfieldV_ListOff" size="123"',
             'id="listfieldH_ListOn" size="123"',
@@ -335,12 +335,12 @@ public function test_new_extra(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->listField("ListfieldV", "listfieldV", $this->aElements, null, null, null, null, null, 'data-old="123"');
         $form->listField("ListfieldH", "listfieldH", $this->aElements, null, null, null, null, null, 'data-old="123"', false);
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'id="listfieldV_ListOn" size="4" multiple="multiple" data-old="123"',
             'id="listfieldV_ListOff" size="4" multiple="multiple" data-old="123"',
             'id="listfieldH_ListOn" size="4" multiple="multiple" data-old="123"',
diff --git a/tests/uts/formhandler_LookAndFeelTest.php b/tests/uts/formhandler_LookAndFeelTest.php
index 850ded5..dff2638 100644
--- a/tests/uts/formhandler_LookAndFeelTest.php
+++ b/tests/uts/formhandler_LookAndFeelTest.php
@@ -14,7 +14,7 @@ public function test_addHTML(): void
                 "  </tr>"
         );
 
-        $this->assertFormFlushContains($form, "<td colspan='3'><hr size='1' /></td>");
+        static::assertFormFlushContains($form, "<td colspan='3'><hr size='1' /></td>");
     }
 
     public function test_addLine(): void
@@ -24,7 +24,7 @@ public function test_addLine(): void
         $form->addLine();
         $form->addLine("theline");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             "<tr><td>&nbsp;</td><td>&nbsp;</td><td></td></tr>",
             "<tr><td>&nbsp;</td><td>&nbsp;</td><td>theline</td></tr>"
         ]);
@@ -38,7 +38,7 @@ public function test_useTable(): void
 
         $t = (string)$form->flush(true);
 
-        $this->assertNotEquals("table", $t);
+        static::assertNotEquals("table", $t);
     }
 
     public function test_setMask(): void
@@ -57,7 +57,7 @@ public function test_setMask(): void
         $form->textField("Textfield4", "textfield4");
         $form->setValue("textfield4", "value4");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Textfield||:||<input type="text" name="textfield" id="textfield" value="value" size="20" />||textfield||||error_textfield||',
             'Textfield2:<input type="text" name="textfield2" id="textfield2" value="value2" size="20" />error_textfield2',
             'Textfield3--:--<input type="text" name="textfield3" id="textfield3" value="value3" size="20" />--%name----error_textfield3--',
@@ -76,7 +76,7 @@ public function test_setErrorMessage(): void
         $form->setErrorMessage("textfield2", "this is another individual errormessage", false);
         $form->setError("textfield2", "error2");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Textfield:<input type="text" name="textfield" id="textfield" value="" size="20" />error_textfield<span id="error_textfield" class="error">this is an individual errormessage</span>',
             'Textfield2:<input type="text" name="textfield2" id="textfield2" value="" size="20" />error_textfield2this is another individual errormessage'
         ]);
@@ -90,11 +90,11 @@ public function test_setLanguage(): void
         $form = new FormHandler();
         $form->setLanguage('nl');
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->textField("Textfield", "textfield", FH_DIGIT);
 
-        $this->assertFormFlushContains($form, ['De opgegeven waarde is ongeldig!']);
+        static::assertFormFlushContains($form, ['De opgegeven waarde is ongeldig!']);
     }
 
     public function test_catchErrors(): void
@@ -105,17 +105,17 @@ public function test_catchErrors(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->textField("Textfield", "textfield", FH_DIGIT);
 
         $errors = $form->catchErrors();
 
-        $this->assertEquals('textfield-You did not enter a correct value for this field!', $errors['textfield']);
+        static::assertEquals('textfield-You did not enter a correct value for this field!', $errors['textfield']);
 
         $t = (string)$form->flush(true);
 
-        $this->assertFalse(strpos($t, "You did not enter a correct value for this field!"));
+        static::assertFalse(strpos($t, "You did not enter a correct value for this field!"));
     }
 
     public function test_catchErrors2(): void
@@ -126,15 +126,15 @@ public function test_catchErrors2(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->textField("Textfield", "textfield", FH_DIGIT);
 
         $errors = $form->catchErrors(true);
 
-        $this->assertEquals('textfield-You did not enter a correct value for this field!', $errors['textfield']);
+        static::assertEquals('textfield-You did not enter a correct value for this field!', $errors['textfield']);
 
-        $this->assertFormFlushContains($form, ['Textfield:<input type="text" name="textfield" id="textfield" value="textvalue" size="20" class="error" />error_textfieldtextfield-You did not enter a correct value for this field!']);
+        static::assertFormFlushContains($form, ['Textfield:<input type="text" name="textfield" id="textfield" value="textvalue" size="20" class="error" />error_textfieldtextfield-You did not enter a correct value for this field!']);
     }
 
     public function test_setTableSettings(): void
@@ -145,6 +145,6 @@ public function test_setTableSettings(): void
 
         $form->textField("Textfield", "textfield", FH_DIGIT);
 
-        $this->assertFormFlushContains($form, ["<table border='0' cellspacing='2' cellpadding='2' width='400'  style='border: 1px solid green'>"]);
+        static::assertFormFlushContains($form, ["<table border='0' cellspacing='2' cellpadding='2' width='400'  style='border: 1px solid green'>"]);
     }
 };
diff --git a/tests/uts/formhandler_LookAndFeel_FieldsetTest.php b/tests/uts/formhandler_LookAndFeel_FieldsetTest.php
index 6c4f9ad..9d34420 100644
--- a/tests/uts/formhandler_LookAndFeel_FieldsetTest.php
+++ b/tests/uts/formhandler_LookAndFeel_FieldsetTest.php
@@ -11,7 +11,7 @@ public function test(): void
         $form->borderStart();
         $form->borderStop();
 
-        $this->assertFormFlushContains($form, "BEGINfieldset1END");
+        static::assertFormFlushContains($form, "BEGINfieldset1END");
     }
 
     public function test_entries(): void
@@ -22,7 +22,7 @@ public function test_entries(): void
         $form->textField("Textfield", "textfield");
         $form->borderStop();
 
-        $this->assertFormFlushContains($form, 'BEGINfieldset1Textfield:<input type="text" name="textfield" id="textfield" value="" size="20" />error_textfieldEND');
+        static::assertFormFlushContains($form, 'BEGINfieldset1Textfield:<input type="text" name="textfield" id="textfield" value="" size="20" />error_textfieldEND');
     }
 
     public function test_Caption(): void
@@ -32,7 +32,7 @@ public function test_Caption(): void
         $form->borderStart("thecaption");
         $form->borderStop();
 
-        $this->assertFormFlushContains($form, "BEGINfieldset1thecaptionEND");
+        static::assertFormFlushContains($form, "BEGINfieldset1thecaptionEND");
     }
 
     public function test_Name(): void
@@ -42,7 +42,7 @@ public function test_Name(): void
         $form->borderStart(null, "thename");
         $form->borderStop();
 
-        $this->assertFormFlushContains($form, "BEGINthenameEND");
+        static::assertFormFlushContains($form, "BEGINthenameEND");
     }
 
     public function test_Extra(): void
@@ -52,6 +52,6 @@ public function test_Extra(): void
         $form->borderStart(null, null, 'data-old="123"');
         $form->borderStop();
 
-        $this->assertFormFlushContains($form, 'BEGINfieldset1data-old="123"END');
+        static::assertFormFlushContains($form, 'BEGINfieldset1data-old="123"END');
     }
 };
diff --git a/tests/uts/formhandler_LookAndFeel_newPageTest.php b/tests/uts/formhandler_LookAndFeel_newPageTest.php
index db4c76f..6eb12f5 100644
--- a/tests/uts/formhandler_LookAndFeel_newPageTest.php
+++ b/tests/uts/formhandler_LookAndFeel_newPageTest.php
@@ -22,7 +22,7 @@ public function test(): void
         $form->textField("Question 3", "q3", FH_STRING);
         $form->submitButton("Submit");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             '<input type="hidden" name="q2" id="q2" value="" />',
             '<input type="hidden" name="q3" id="q3" value="" />',
             '<input type="hidden" name="FormHandler_page" id="FormHandler_page" value="1" />',
@@ -55,7 +55,7 @@ public function test_page2(): void
         $form->textField("Question 3", "q3", FH_STRING);
         $form->submitButton("Submit");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             '<input type="hidden" name="q1" id="q1" value="anwser1" />',
             '<input type="hidden" name="q3" id="q3" value="" />',
             '<input type="hidden" name="FormHandler_page" id="FormHandler_page" value="2" />',
@@ -88,7 +88,7 @@ public function test_page3(): void
         $form->textField("Question 3", "q3", FH_STRING);
         $form->submitButton("Submit");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             '<input type="hidden" name="q1" id="q1" value="anwser1" />',
             '<input type="hidden" name="q2" id="q2" value="answer2" />',
             '<input type="hidden" name="FormHandler_page" id="FormHandler_page" value="3" />',
diff --git a/tests/uts/formhandler_LookAndFeel_setHelpTextTest.php b/tests/uts/formhandler_LookAndFeel_setHelpTextTest.php
index 9eea19a..eb583e7 100644
--- a/tests/uts/formhandler_LookAndFeel_setHelpTextTest.php
+++ b/tests/uts/formhandler_LookAndFeel_setHelpTextTest.php
@@ -11,7 +11,7 @@ public function test(): void
         $form->textField("Textfield", "textfield");
         $form->setHelpText("textfield", "This ist a help text");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'FHTML/overlib/overlib.js',
             'FHTML/overlib/overlib_hideform.js',
             'Textfield:<input type="text" name="textfield" id="textfield" value="" size="20" /><img src="',
@@ -26,7 +26,7 @@ public function test_helpTitle(): void
         $form->textField("Textfield", "textfield");
         $form->setHelpText("textfield", "This ist a help text", "The helptitle");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'FHTML/overlib/overlib.js',
             'FHTML/overlib/overlib_hideform.js',
             'Textfield:<input type="text" name="textfield" id="textfield" value="" size="20" /><img src="',
@@ -42,7 +42,7 @@ public function test_helpIcon(): void
         $form->setHelpText("textfield", "This ist a help text");
         $form->setHelpIcon("theicon.gif");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'FHTML/overlib/overlib.js',
             'FHTML/overlib/overlib_hideform.js',
             'Textfield:<input type="text" name="textfield" id="textfield" value="" size="20" /><img src="theicon.gif" border="0" onmouseover="return overlib(\'This ist a help text\', DELAY, \'400\', FGCOLOR, \'#CCCCCC\', BGCOLOR, \'#666666\', TEXTCOLOR, \'#666666\', TEXTFONT, \'Verdana\', TEXTSIZE, \'12px\', CELLPAD, 8, BORDER, 1, CAPTION, \'&nbsp;Textfield - Help\', CAPTIONSIZE, \'12px\');" onmouseout="return nd();" style="color:333333;cursor:help;" />error_textfield'
diff --git a/tests/uts/formhandler_LookAndFeel_setMaxLengthTest.php b/tests/uts/formhandler_LookAndFeel_setMaxLengthTest.php
index 2b17d5d..f17b359 100644
--- a/tests/uts/formhandler_LookAndFeel_setMaxLengthTest.php
+++ b/tests/uts/formhandler_LookAndFeel_setMaxLengthTest.php
@@ -11,7 +11,7 @@ public function test(): void
         $form->textArea("Textarea", "textarea");
         $form->setMaxLength("textarea", 123);
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'FHTML/js/maxlength.js',
             'Textarea:<textarea name="textarea" id="textarea" cols="40" rows="7"',
             'onkeyup="displayLimit(\'FormHandler\', \'textarea\', 123, true, \'&lt;b&gt;%d&lt;/b&gt; characters remaining on your input limit\');">'
@@ -25,7 +25,7 @@ public function test_noDisplayMessage(): void
         $form->textArea("Textarea", "textarea");
         $form->setMaxLength("textarea", 123, false);
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'FHTML/js/maxlength.js',
             'Textarea:<textarea name="textarea" id="textarea" cols="40" rows="7"',
             'onkeyup="displayLimit(\'FormHandler\', \'textarea\', 123, false, \'&lt;b&gt;%d&lt;/b&gt; characters remaining on your input limit\');">'
diff --git a/tests/uts/formhandler_LookAndFeel_setTabIndexTest.php b/tests/uts/formhandler_LookAndFeel_setTabIndexTest.php
index 600f8ce..540e41f 100644
--- a/tests/uts/formhandler_LookAndFeel_setTabIndexTest.php
+++ b/tests/uts/formhandler_LookAndFeel_setTabIndexTest.php
@@ -14,7 +14,7 @@ public function test_byString(): void
 
         $form->setTabIndex("fld2, fld3, fld1");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Field 1:<input type="text" name="fld1" id="fld1" value="" size="20" tabindex="3" />error_fld1',
             'Field 2:<input type="text" name="fld2" id="fld2" value="" size="20" tabindex="1" />error_fld2',
             'Field 3:<input type="text" name="fld3" id="fld3" value="" size="20" tabindex="2" />error_fld3'
@@ -37,7 +37,7 @@ public function test_byArray(): void
 
         $form->setTabIndex($tabs);
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Field 1:<input type="text" name="fld1" id="fld1" value="" size="20" tabindex="3" />error_fld1',
             'Field 2:<input type="text" name="fld2" id="fld2" value="" size="20" tabindex="1" />error_fld2',
             'Field 3:<input type="text" name="fld3" id="fld3" value="" size="20" tabindex="2" />error_fld3'
@@ -60,7 +60,7 @@ public function test_byArray2(): void
 
         $form->setTabIndex($tabs);
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Field 1:<input type="text" name="fld1" id="fld1" value="" size="20" tabindex="3" />error_fld1',
             'Field 2:<input type="text" name="fld2" id="fld2" value="" size="20" tabindex="1" />error_fld2',
             'Field 3:<input type="text" name="fld3" id="fld3" value="" size="20" tabindex="2" />error_fld3'
@@ -85,7 +85,7 @@ public function test_byArray3(): void
 
         $form->setTabIndex($tabs);
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Field 1:<input type="text" name="fld1" id="fld1" value="" size="20" tabindex="3" />error_fld1',
             'Field 2:<input type="text" name="fld2" id="fld2" value="" size="20" tabindex="1" />error_fld2',
             'Field 3:<input type="text" name="fld3" id="fld3" value="" size="20" tabindex="2" />error_fld3'
diff --git a/tests/uts/formhandler_PassFieldTest.php b/tests/uts/formhandler_PassFieldTest.php
index 0337320..80ffca1 100644
--- a/tests/uts/formhandler_PassFieldTest.php
+++ b/tests/uts/formhandler_PassFieldTest.php
@@ -8,13 +8,13 @@ public function test_new(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->passField("Passfield", "passfield");
 
-        $this->assertEmpty($form->getValue("passfield"));
+        static::assertEmpty($form->getValue("passfield"));
 
-        $this->assertFormFlushContains($form, ['Passfield:<input type="password" name="passfield" id="passfield" size="20" />error_passfield']);
+        static::assertFormFlushContains($form, ['Passfield:<input type="password" name="passfield" id="passfield" size="20" />error_passfield']);
     }
 
     public function test_posted(): void
@@ -24,11 +24,11 @@ public function test_posted(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->passField("Passfield", "passfield");
 
-        $this->assertEquals("passvalue", $form->getValue("passfield"));
+        static::assertEquals("passvalue", $form->getValue("passfield"));
     }
 
     public function test_posted_fillvalue_byinvalid(): void
@@ -38,15 +38,15 @@ public function test_posted_fillvalue_byinvalid(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->passField("Passfield", "passfield");
 
-        $this->assertEquals("passvalue", $form->getValue("passfield"));
+        static::assertEquals("passvalue", $form->getValue("passfield"));
 
         $form->setError("passfield", "forcedError");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Passfield:<input type="password" name="passfield" id="passfield" size="20" class="error" />error_passfield',
             '<span id="error_passfield" class="error">forcedError</span>'
         ]);
@@ -58,15 +58,15 @@ public function test_validator(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->passField("Passfield", "passfield", FH_NOT_EMPTY);
 
-        $this->assertEmpty($form->getValue("passfield"));
+        static::assertEmpty($form->getValue("passfield"));
 
         $t = $form->catchErrors(false);
 
-        $this->assertEquals(
+        static::assertEquals(
             '<span id="error_passfield" class="error">You did not enter a correct value for this field!</span>',
             $t['passfield']
         );
@@ -76,38 +76,38 @@ public function test_new_size(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->passField("Passfield", "passfield", null, 123);
 
-        $this->assertEmpty($form->getValue("passfield"));
+        static::assertEmpty($form->getValue("passfield"));
 
-        $this->assertFormFlushContains($form, ['Passfield:<input type="password" name="passfield" id="passfield" size="123" />error_passfield']);
+        static::assertFormFlushContains($form, ['Passfield:<input type="password" name="passfield" id="passfield" size="123" />error_passfield']);
     }
 
     public function test_new_maxlength(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->passField("Passfield", "passfield", null, null, 123);
 
-        $this->assertEmpty($form->getValue("passfield"));
+        static::assertEmpty($form->getValue("passfield"));
 
-        $this->assertFormFlushContains($form, ['Passfield:<input type="password" name="passfield" id="passfield" size="20" maxlength="123" />error_passfield']);
+        static::assertFormFlushContains($form, ['Passfield:<input type="password" name="passfield" id="passfield" size="20" maxlength="123" />error_passfield']);
     }
 
     public function test_new_extra(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->passField("Passfield", "passfield", null, null, null, 'data-old="123"');
 
-        $this->assertEmpty($form->getValue("passfield"));
+        static::assertEmpty($form->getValue("passfield"));
 
-        $this->assertFormFlushContains($form, ['Passfield:<input type="password" name="passfield" id="passfield" size="20" data-old="123" />error_passfield']);
+        static::assertFormFlushContains($form, ['Passfield:<input type="password" name="passfield" id="passfield" size="20" data-old="123" />error_passfield']);
     }
 };
diff --git a/tests/uts/formhandler_RadiobuttonTest.php b/tests/uts/formhandler_RadiobuttonTest.php
index 755e28a..75c99df 100644
--- a/tests/uts/formhandler_RadiobuttonTest.php
+++ b/tests/uts/formhandler_RadiobuttonTest.php
@@ -14,13 +14,13 @@ public function test_new(): void
 
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->radioButton("Radiobutton", "radiobutton", $aRadiobuttons);
 
-        $this->assertEmpty($form->getValue("radiobutton"));
+        static::assertEmpty($form->getValue("radiobutton"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Radiobutton:<input type="radio" name="radiobutton" id="radiobutton_1" value="a" /><label for="radiobutton_1" class="noStyle">Button1</label>',
             '<input type="radio" name="radiobutton" id="radiobutton_2" value="b" /><label for="radiobutton_2" class="noStyle">Button2</label>',
             '<input type="radio" name="radiobutton" id="radiobutton_3" value="c" /><label for="radiobutton_3" class="noStyle">Button3</label>',
@@ -37,12 +37,12 @@ public function test_new_defaultValue(): void
 
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->radioButton("Radiobutton", "radiobutton", $aRadiobuttons);
         $form->setValue("radiobutton", "c");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Radiobutton:<input type="radio" name="radiobutton" id="radiobutton_1" value="a" /><label for="radiobutton_1" class="noStyle">Button1</label>',
             '<input type="radio" name="radiobutton" id="radiobutton_2" value="b" /><label for="radiobutton_2" class="noStyle">Button2</label>',
             '<input type="radio" name="radiobutton" id="radiobutton_3" value="c" checked="checked" /><label for="radiobutton_3" class="noStyle">Button3</label>',
@@ -60,12 +60,12 @@ public function test_new_useArrayKeyAsValueFalse(): void
 
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->radioButton("Radiobutton", "radiobutton", $aRadiobuttons, null, false);
         $form->setValue("radiobutton", "Button2");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Radiobutton:<input type="radio" name="radiobutton" id="radiobutton_1" value="Button1" /><label for="radiobutton_1" class="noStyle">Button1</label>',
             '<input type="radio" name="radiobutton" id="radiobutton_2" value="Button2" checked="checked" /><label for="radiobutton_2" class="noStyle">Button2</label>',
             '<input type="radio" name="radiobutton" id="radiobutton_3" value="Button3" /><label for="radiobutton_3" class="noStyle">Button3</label>',
@@ -83,12 +83,12 @@ public function test_new_useArrayKeyAsValueFalse_defaultValue(): void
 
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->radioButton("Radiobutton", "radiobutton", $aRadiobuttons);
         $form->setValue("radiobutton", "c");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Radiobutton:<input type="radio" name="radiobutton" id="radiobutton_1" value="a" /><label for="radiobutton_1" class="noStyle">Button1</label>',
             '<input type="radio" name="radiobutton" id="radiobutton_2" value="b" /><label for="radiobutton_2" class="noStyle">Button2</label>',
             '<input type="radio" name="radiobutton" id="radiobutton_3" value="c" checked="checked" /><label for="radiobutton_3" class="noStyle">Button3</label>',
@@ -107,13 +107,13 @@ public function test_new_extra(): void
 
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->radioButton("Radiobutton", "radiobutton", $aRadiobuttons, null, null, 'data-extra="true"');
 
-        $this->assertEmpty($form->getValue("radiobutton"));
+        static::assertEmpty($form->getValue("radiobutton"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Radiobutton:<input type="radio" name="radiobutton" id="radiobutton_1" value="a" data-extra="true" /><label for="radiobutton_1" class="noStyle">Button1</label>',
             '<input type="radio" name="radiobutton" id="radiobutton_2" value="b" data-extra="true" /><label for="radiobutton_2" class="noStyle">Button2</label>',
             '<input type="radio" name="radiobutton" id="radiobutton_3" value="c" data-extra="true" /><label for="radiobutton_3" class="noStyle">Button3</label>',
@@ -131,13 +131,13 @@ public function test_new_mask(): void
 
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->radioButton("Radiobutton", "radiobutton", $aRadiobuttons, null, null, null, "%field%ABC");
 
-        $this->assertEmpty($form->getValue("radiobutton"));
+        static::assertEmpty($form->getValue("radiobutton"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Radiobutton:<input type="radio" name="radiobutton" id="radiobutton_1" value="a" /><label for="radiobutton_1" class="noStyle">Button1</label>ABC',
             '<input type="radio" name="radiobutton" id="radiobutton_2" value="b" /><label for="radiobutton_2" class="noStyle">Button2</label>ABC',
             '<input type="radio" name="radiobutton" id="radiobutton_3" value="c" /><label for="radiobutton_3" class="noStyle">Button3</label>ABC',
@@ -158,11 +158,11 @@ public function test_posted(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->radioButton("Radiobutton", "radiobutton", $aRadiobuttons);
 
-        $this->assertEquals("b", $form->getValue("radiobutton"));
+        static::assertEquals("b", $form->getValue("radiobutton"));
     }
 
     public function test_posted_fillvalue_byinvalid(): void
@@ -178,14 +178,14 @@ public function test_posted_fillvalue_byinvalid(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->radioButton("Radiobutton", "radiobutton", $aRadiobuttons);
 
-        $this->assertEquals("b", $form->getValue("radiobutton"));
+        static::assertEquals("b", $form->getValue("radiobutton"));
 
         $form->setError("radiobutton", "forcedError");
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Radiobutton:<input type="radio" name="radiobutton" id="radiobutton_1" value="a" /><label for="radiobutton_1" class="error noStyle">Button1</label>',
             '<input type="radio" name="radiobutton" id="radiobutton_2" value="b" checked="checked" /><label for="radiobutton_2" class="error noStyle">Button2</label>',
             '<input type="radio" name="radiobutton" id="radiobutton_3" value="c" /><label for="radiobutton_3" class="error noStyle">Button3</label>',
@@ -206,14 +206,14 @@ public function test_posted_fillvalue_byinvalid_useArrayKeyAsValueFalse(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->radioButton("Radiobutton", "radiobutton", $aRadiobuttons, null, false);
 
-        $this->assertEquals("Button2", $form->getValue("radiobutton"));
+        static::assertEquals("Button2", $form->getValue("radiobutton"));
 
         $form->setError("radiobutton", "forcedError");
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Radiobutton:<input type="radio" name="radiobutton" id="radiobutton_1" value="Button1" /><label for="radiobutton_1" class="error noStyle">Button1</label>',
             '<input type="radio" name="radiobutton" id="radiobutton_2" value="Button2" checked="checked" /><label for="radiobutton_2" class="error noStyle">Button2</label>',
             '<input type="radio" name="radiobutton" id="radiobutton_3" value="Button3" /><label for="radiobutton_3" class="error noStyle">Button3</label>',
@@ -233,15 +233,15 @@ public function test_validator(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->radioButton("Radiobutton", "radiobutton", $aRadiobuttons, FH_NOT_EMPTY);
 
-        $this->assertEmpty($form->getValue("radiobutton"));
+        static::assertEmpty($form->getValue("radiobutton"));
 
         $t = $form->catchErrors(false);
 
-        $this->assertEquals(
+        static::assertEquals(
             '<span id="error_radiobutton" class="error">You did not enter a correct value for this field!</span>',
             $t['radiobutton']
         );
diff --git a/tests/uts/formhandler_SelectFieldTest.php b/tests/uts/formhandler_SelectFieldTest.php
index 08a000b..fdf6e11 100644
--- a/tests/uts/formhandler_SelectFieldTest.php
+++ b/tests/uts/formhandler_SelectFieldTest.php
@@ -14,13 +14,13 @@ public function test_new(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->selectField("Selectfield", "selectfield", $this->aOptions, null, true);
 
-        $this->assertEmpty($form->getValue("selectfield"));
+        static::assertEmpty($form->getValue("selectfield"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Selectfield:<select name="selectfield" id="selectfield" size="1">',
             '<option  value="o1" >Option1</option>',
             '<option  value="o2" >Option2</option>',
@@ -33,13 +33,13 @@ public function test_new_multiple(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->selectField("Selectfield", "selectfield", $this->aOptions, null, true, true);
 
-        $this->assertEmpty($form->getValue("selectfield"));
+        static::assertEmpty($form->getValue("selectfield"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Selectfield:<select name="selectfield[]" id="selectfield" size="4" multiple="multiple">',
             '<option  value="o1" >Option1</option>',
             '<option  value="o2" >Option2</option>',
@@ -57,13 +57,13 @@ public function test_new_label(): void
         $aOptions['o6'] = 'Option6';
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->selectField("Selectfield", "selectfield", $aOptions, null, true);
 
-        $this->assertEmpty($form->getValue("selectfield"));
+        static::assertEmpty($form->getValue("selectfield"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Selectfield:<select name="selectfield" id="selectfield" size="1">',
             '<optgroup label="Label1">',
             '<option  value="o1" >Option1</option>',
@@ -81,13 +81,13 @@ public function test_new_ArrayKeyAsValue_false(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->selectField("Selectfield", "selectfield", $this->aOptions, null, false);
 
-        $this->assertEmpty($form->getValue("selectfield"));
+        static::assertEmpty($form->getValue("selectfield"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Selectfield:<select name="selectfield" id="selectfield" size="1">',
             '<option  value="Option1" >Option1</option>',
             '<option  value="Option2" >Option2</option>',
@@ -103,13 +103,13 @@ public function test_posted(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->selectField("Selectfield", "selectfield", $this->aOptions);
 
-        $this->assertEquals("o1", $form->getValue("selectfield"));
+        static::assertEquals("o1", $form->getValue("selectfield"));
 
-        $this->assertTrue($form->isCorrect());
+        static::assertTrue($form->isCorrect());
     }
 
     public function test_posted_fillvalue_byinvalid(): void
@@ -119,15 +119,15 @@ public function test_posted_fillvalue_byinvalid(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->selectField("Selectfield", "selectfield", $this->aOptions);
 
-        $this->assertEquals("o1", $form->getValue("selectfield"));
+        static::assertEquals("o1", $form->getValue("selectfield"));
 
         $form->setError("selectfield", "forcedError");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Selectfield:<select class="error" name="selectfield" id="selectfield" size="1">',
             '<option  value="o1"  selected="selected">Option1</option>',
             '<option  value="o2" >Option2</option>',
@@ -143,15 +143,15 @@ public function test_posted_multiple_fillvalue_byinvalid(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->selectField("Selectfield", "selectfield", $this->aOptions, null, null, true);
 
-        $this->assertEquals(["o1", "o3"], $form->getValue("selectfield"));
+        static::assertEquals(["o1", "o3"], $form->getValue("selectfield"));
 
         $form->setError("selectfield", "forcedError");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Selectfield:<select class="error" name="selectfield[]" id="selectfield" size="4" multiple="multiple">',
             '<option  value="o1"  selected="selected">Option1</option>',
             '<option  value="o2" >Option2</option>',
@@ -164,13 +164,13 @@ public function test_new_size(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->selectField("Selectfield", "selectfield", $this->aOptions, null, true, null, 2);
 
-        $this->assertEmpty($form->getValue("selectfield"));
+        static::assertEmpty($form->getValue("selectfield"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Selectfield:<select name="selectfield" id="selectfield" size="2">',
             '<option  value="o1" >Option1</option>',
             '<option  value="o2" >Option2</option>',
@@ -182,13 +182,13 @@ public function test_new_extra(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->selectField("Selectfield", "selectfield", $this->aOptions, null, true, null, null, 'data-old="123"');
 
-        $this->assertEmpty($form->getValue("selectfield"));
+        static::assertEmpty($form->getValue("selectfield"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Selectfield:<select name="selectfield" id="selectfield" size="1" data-old="123">',
             '<option  value="o1" >Option1</option>',
             '<option  value="o2" >Option2</option>',
diff --git a/tests/uts/formhandler_SetFocusTest.php b/tests/uts/formhandler_SetFocusTest.php
index 350cc0a..68b7a62 100644
--- a/tests/uts/formhandler_SetFocusTest.php
+++ b/tests/uts/formhandler_SetFocusTest.php
@@ -11,7 +11,7 @@ public function test_default(): void
         $form->textField("Textfield", "textfield");
         $form->textField("Textfield2", "textfield2");
 
-        $this->assertFormFlushContains(
+        static::assertFormFlushContains(
             $form,
             "// set the focus on a specific field \n" .
                 "var elem = document.getElementById ? document.getElementById('textfield'): document.all? document.all['textfield']: false; \n" .
@@ -30,8 +30,8 @@ public function test_set(): void
         $form->textField("Textfield", "textfield");
         $form->textField("Textfield2", "textfield2");
 
-        $this->assertTrue($form->setFocus("textfield2"));
-        $this->assertFormFlushContains(
+        static::assertTrue($form->setFocus("textfield2"));
+        static::assertFormFlushContains(
             $form,
             "// set the focus on a specific field \n" .
                 "var elem = document.getElementById ? document.getElementById('textfield2'): document.all? document.all['textfield2']: false; \n" .
@@ -50,10 +50,10 @@ public function test_nofocus(): void
         $form->textField("Textfield", "textfield");
         $form->textField("Textfield2", "textfield2");
 
-        $this->assertTrue($form->setFocus(false));
+        static::assertTrue($form->setFocus(false));
 
         $t = $form->flush(true);
-        $this->assertFalse(strpos($t, "elem.focus()"));
+        static::assertFalse(strpos($t, "elem.focus()"));
     }
 
     public function test_nofield(): void
@@ -70,9 +70,9 @@ public function test_set_specialfield_datefield(): void
 
         $form->dateField("Field", "field");
 
-        $this->assertTrue($form->setFocus("field"));
+        static::assertTrue($form->setFocus("field"));
 
-        $this->assertFormFlushContains(
+        static::assertFormFlushContains(
             $form,
             "// set the focus on a specific field \n" .
                 "var elem = document.getElementById ? document.getElementById('field_day'): document.all? document.all['field_day']: false; \n" .
@@ -90,9 +90,9 @@ public function test_set_specialfield_jsdatefield(): void
 
         $form->jsDateField("Field", "field");
 
-        $this->assertTrue($form->setFocus("field"));
+        static::assertTrue($form->setFocus("field"));
 
-        $this->assertFormFlushContains(
+        static::assertFormFlushContains(
             $form,
             "// set the focus on a specific field \n" .
                 "var elem = document.getElementById ? document.getElementById('field_day'): document.all? document.all['field_day']: false; \n" .
@@ -110,9 +110,9 @@ public function test_set_specialfield_listfield(): void
 
         $form->listField("Field", "field", []);
 
-        $this->assertTrue($form->setFocus("field"));
+        static::assertTrue($form->setFocus("field"));
 
-        $this->assertFormFlushContains(
+        static::assertFormFlushContains(
             $form,
             "// set the focus on a specific field \n" .
                 "var elem = document.getElementById ? document.getElementById('field_ListOn'): document.all? document.all['field_ListOn']: false; \n" .
@@ -130,9 +130,9 @@ public function test_set_spezialfield_timefield(): void
 
         $form->timeField("Field", "field");
 
-        $this->assertTrue($form->setFocus("field"));
+        static::assertTrue($form->setFocus("field"));
 
-        $this->assertFormFlushContains(
+        static::assertFormFlushContains(
             $form,
             "// set the focus on a specific field \n" .
                 "var elem = document.getElementById ? document.getElementById('field_hour'): document.all? document.all['field_hour']: false; \n" .
@@ -149,30 +149,30 @@ public function test_np_focus_possible(): void
         $form = new FormHandler();
 
         $form->editor("Editor", "editor");
-        $this->assertFalse($form->setFocus("editor"));
+        static::assertFalse($form->setFocus("editor"));
 
         $form->radioButton("Radiobutton", "radiobutton", []);
-        $this->assertFalse($form->setFocus("radiobutton"));
+        static::assertFalse($form->setFocus("radiobutton"));
 
         $form->checkBox("Checkbox", "checkbox");
-        $this->assertFalse($form->setFocus("checkbox"));
+        static::assertFalse($form->setFocus("checkbox"));
 
         $form->hiddenField("hiddenfield", "val");
-        $this->assertFalse($form->setFocus("hiddenfield"));
+        static::assertFalse($form->setFocus("hiddenfield"));
 
         $form->submitButton("Submitbutton", "submitbutton");
-        $this->assertFalse($form->setFocus("submitbutton"));
+        static::assertFalse($form->setFocus("submitbutton"));
 
         $form->resetButton("Resetbutton", "resetbutton");
-        $this->assertFalse($form->setFocus("resetbutton"));
+        static::assertFalse($form->setFocus("resetbutton"));
 
         $form->imageButton("Imagebutton", "imagebutton");
-        $this->assertFalse($form->setFocus("imagebutton"));
+        static::assertFalse($form->setFocus("imagebutton"));
 
         $form->button("Button", "button");
-        $this->assertFalse($form->setFocus("button"));
+        static::assertFalse($form->setFocus("button"));
 
         $t = $form->flush(true);
-        $this->assertFalse(strpos($t, "elem.focus()"));
+        static::assertFalse(strpos($t, "elem.focus()"));
     }
 };
diff --git a/tests/uts/formhandler_TextAreaTest.php b/tests/uts/formhandler_TextAreaTest.php
index f764218..27671c6 100644
--- a/tests/uts/formhandler_TextAreaTest.php
+++ b/tests/uts/formhandler_TextAreaTest.php
@@ -8,13 +8,13 @@ public function test_new(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->textArea("Textarea", "textarea");
 
-        $this->assertEmpty($form->getValue("textarea"));
+        static::assertEmpty($form->getValue("textarea"));
 
-        $this->assertFormFlushContains($form, ['Textarea:<textarea name="textarea" id="textarea" cols="40" rows="7"></textarea>error_textarea']);
+        static::assertFormFlushContains($form, ['Textarea:<textarea name="textarea" id="textarea" cols="40" rows="7"></textarea>error_textarea']);
     }
 
     public function test_posted(): void
@@ -24,11 +24,11 @@ public function test_posted(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->textArea("Textarea", "textarea");
 
-        $this->assertEquals("text\nvalue", $form->getValue("textarea"));
+        static::assertEquals("text\nvalue", $form->getValue("textarea"));
     }
 
     public function test_posted_fillvalue_byinvalid(): void
@@ -38,15 +38,15 @@ public function test_posted_fillvalue_byinvalid(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->textArea("Textarea", "textarea");
 
-        $this->assertEquals("textvalue", $form->getValue("textarea"));
+        static::assertEquals("textvalue", $form->getValue("textarea"));
 
         $form->setError("textarea", "forcedError");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Textarea:<textarea class="error" name="textarea" id="textarea" cols="40" rows="7">textvalue</textarea>error_textarea',
             '<span id="error_textarea" class="error">forcedError</span>'
         ]);
@@ -58,15 +58,15 @@ public function test_validator(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->textArea("Textarea", "textarea", FH_NOT_EMPTY);
 
-        $this->assertEmpty($form->getValue("textarea"));
+        static::assertEmpty($form->getValue("textarea"));
 
         $t = $form->catchErrors(false);
 
-        $this->assertEquals(
+        static::assertEquals(
             '<span id="error_textarea" class="error">You did not enter a correct value for this field!</span>',
             $t['textarea']
         );
@@ -76,38 +76,38 @@ public function test_new_cols(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->textArea("Textarea", "textarea", null, 123);
 
-        $this->assertEmpty($form->getValue("textarea"));
+        static::assertEmpty($form->getValue("textarea"));
 
-        $this->assertFormFlushContains($form, ['Textarea:<textarea name="textarea" id="textarea" cols="123" rows="7"></textarea>error_textarea']);
+        static::assertFormFlushContains($form, ['Textarea:<textarea name="textarea" id="textarea" cols="123" rows="7"></textarea>error_textarea']);
     }
 
     public function test_new_maxlength(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->textArea("Textarea", "textarea", null, null, 123);
 
-        $this->assertEmpty($form->getValue("textarea"));
+        static::assertEmpty($form->getValue("textarea"));
 
-        $this->assertFormFlushContains($form, ['Textarea:<textarea name="textarea" id="textarea" cols="40" rows="123"></textarea>error_textarea']);
+        static::assertFormFlushContains($form, ['Textarea:<textarea name="textarea" id="textarea" cols="40" rows="123"></textarea>error_textarea']);
     }
 
     public function test_new_extra(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->textArea("Textarea", "textarea", null, null, null, 'data-old="123"');
 
-        $this->assertEmpty($form->getValue("textarea"));
+        static::assertEmpty($form->getValue("textarea"));
 
-        $this->assertFormFlushContains($form, ['Textarea:<textarea name="textarea" id="textarea" cols="40" rows="7" data-old="123"></textarea>error_textarea']);
+        static::assertFormFlushContains($form, ['Textarea:<textarea name="textarea" id="textarea" cols="40" rows="7" data-old="123"></textarea>error_textarea']);
     }
 };
diff --git a/tests/uts/formhandler_TextFieldTest.php b/tests/uts/formhandler_TextFieldTest.php
index 79b4c9f..284144a 100644
--- a/tests/uts/formhandler_TextFieldTest.php
+++ b/tests/uts/formhandler_TextFieldTest.php
@@ -8,13 +8,13 @@ public function test_new(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->textField("Textfield", "textfield");
 
-        $this->assertEmpty($form->getValue("textfield"));
+        static::assertEmpty($form->getValue("textfield"));
 
-        $this->assertFormFlushContains($form, ['Textfield:<input type="text" name="textfield" id="textfield" value="" size="20" />error_textfield']);
+        static::assertFormFlushContains($form, ['Textfield:<input type="text" name="textfield" id="textfield" value="" size="20" />error_textfield']);
     }
 
     public function test_posted(): void
@@ -24,11 +24,11 @@ public function test_posted(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->textField("Textfield", "textfield");
 
-        $this->assertEquals("textvalue", $form->getValue("textfield"));
+        static::assertEquals("textvalue", $form->getValue("textfield"));
     }
 
     public function test_posted_fillvalue_byinvalid(): void
@@ -38,15 +38,15 @@ public function test_posted_fillvalue_byinvalid(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->textField("Textfield", "textfield");
 
-        $this->assertEquals("textvalue", $form->getValue("textfield"));
+        static::assertEquals("textvalue", $form->getValue("textfield"));
 
         $form->setError("textfield", "forcedError");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Textfield:<input type="text" name="textfield" id="textfield" value="textvalue" size="20" class="error" />error_textfield',
             '<span id="error_textfield" class="error">forcedError</span>'
         ]);
@@ -58,15 +58,15 @@ public function test_validator(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->textField("Textfield", "textfield", FH_NOT_EMPTY);
 
-        $this->assertEmpty($form->getValue("textfield"));
+        static::assertEmpty($form->getValue("textfield"));
 
         $t = $form->catchErrors(false);
 
-        $this->assertEquals(
+        static::assertEquals(
             '<span id="error_textfield" class="error">You did not enter a correct value for this field!</span>',
             $t['textfield']
         );
@@ -76,38 +76,38 @@ public function test_new_size(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->textField("Textfield", "textfield", null, 123);
 
-        $this->assertEmpty($form->getValue("textfield"));
+        static::assertEmpty($form->getValue("textfield"));
 
-        $this->assertFormFlushContains($form, ['Textfield:<input type="text" name="textfield" id="textfield" value="" size="123" />error_textfield']);
+        static::assertFormFlushContains($form, ['Textfield:<input type="text" name="textfield" id="textfield" value="" size="123" />error_textfield']);
     }
 
     public function test_new_maxlength(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->textField("Textfield", "textfield", null, null, 123);
 
-        $this->assertEmpty($form->getValue("textfield"));
+        static::assertEmpty($form->getValue("textfield"));
 
-        $this->assertFormFlushContains($form, ['Textfield:<input type="text" name="textfield" id="textfield" value="" size="20" maxlength="123" />error_textfield']);
+        static::assertFormFlushContains($form, ['Textfield:<input type="text" name="textfield" id="textfield" value="" size="20" maxlength="123" />error_textfield']);
     }
 
     public function test_new_extra(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->textField("Textfield", "textfield", null, null, null, 'data-old="123"');
 
-        $this->assertEmpty($form->getValue("textfield"));
+        static::assertEmpty($form->getValue("textfield"));
 
-        $this->assertFormFlushContains($form, ['Textfield:<input type="text" name="textfield" id="textfield" value="" size="20"  data-old="123"']);
+        static::assertFormFlushContains($form, ['Textfield:<input type="text" name="textfield" id="textfield" value="" size="20"  data-old="123"']);
     }
 };
diff --git a/tests/uts/formhandler_TextSelectFieldTest.php b/tests/uts/formhandler_TextSelectFieldTest.php
index 7b64dae..d7775b6 100644
--- a/tests/uts/formhandler_TextSelectFieldTest.php
+++ b/tests/uts/formhandler_TextSelectFieldTest.php
@@ -17,13 +17,13 @@ public function test_new(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->textSelectField("Textselectfield", "textselectfield", $this->aOptions);
 
-        $this->assertEmpty($form->getValue("textselectfield"));
+        static::assertEmpty($form->getValue("textselectfield"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             "<script type=\"text/javascript\">\n" .
                 "function FH_CLOSE_TEXTSELECT( id )\n" .
                 "{\n" .
@@ -48,13 +48,13 @@ public function test_posted(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->textSelectField("Textselectfield", "textselectfield", $this->aOptions);
 
-        $this->assertEquals("Option2", $form->getValue("textselectfield"));
+        static::assertEquals("Option2", $form->getValue("textselectfield"));
 
-        $this->assertTrue($form->isCorrect());
+        static::assertTrue($form->isCorrect());
     }
 
     public function test_posted_fillvalue_byinvalid(): void
@@ -64,53 +64,53 @@ public function test_posted_fillvalue_byinvalid(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->textSelectField("Textselectfield", "textselectfield", $this->aOptions);
 
-        $this->assertEquals("Option2", $form->getValue("textselectfield"));
+        static::assertEquals("Option2", $form->getValue("textselectfield"));
 
         $form->setError("textselectfield", "forcedError");
 
-        $this->assertFormFlushContains($form, ['Textselectfield:textselectfield-Option2-20---textselectfield-Option1textselectfield-Option2textselectfield-Option3error_textselectfield<span id="error_textselectfield" class="error">forcedError</span>']);
+        static::assertFormFlushContains($form, ['Textselectfield:textselectfield-Option2-20---textselectfield-Option1textselectfield-Option2textselectfield-Option3error_textselectfield<span id="error_textselectfield" class="error">forcedError</span>']);
     }
 
     public function test_new_size(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->textSelectField("Textselectfield", "textselectfield", $this->aOptions, null, 123);
 
-        $this->assertEmpty($form->getValue("textselectfield"));
+        static::assertEmpty($form->getValue("textselectfield"));
 
-        $this->assertFormFlushContains($form, ['Textselectfield:textselectfield--123---textselectfield-Option1textselectfield-Option2textselectfield-Option3error_textselectfield']);
+        static::assertFormFlushContains($form, ['Textselectfield:textselectfield--123---textselectfield-Option1textselectfield-Option2textselectfield-Option3error_textselectfield']);
     }
 
     public function test_new_maxlenght(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->textSelectField("Textselectfield", "textselectfield", $this->aOptions, null, null, 456);
 
-        $this->assertEmpty($form->getValue("textselectfield"));
+        static::assertEmpty($form->getValue("textselectfield"));
 
-        $this->assertFormFlushContains($form, ['Textselectfield:textselectfield--20-maxlength="456" --textselectfield-Option1textselectfield-Option2textselectfield-Option3error_textselectfield']);
+        static::assertFormFlushContains($form, ['Textselectfield:textselectfield--20-maxlength="456" --textselectfield-Option1textselectfield-Option2textselectfield-Option3error_textselectfield']);
     }
 
     public function test_new_extra(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->textSelectField("Textselectfield", "textselectfield", $this->aOptions, null, null, null, 'data-old="123"');
 
-        $this->assertEmpty($form->getValue("textselectfield"));
+        static::assertEmpty($form->getValue("textselectfield"));
 
-        $this->assertFormFlushContains($form, ['Textselectfield:textselectfield--20- data-old="123" --textselectfield-Option1textselectfield-Option2textselectfield-Option3error_textselectfield']);
+        static::assertFormFlushContains($form, ['Textselectfield:textselectfield--20- data-old="123" --textselectfield-Option1textselectfield-Option2textselectfield-Option3error_textselectfield']);
     }
 };
diff --git a/tests/uts/formhandler_TimeFieldTest.php b/tests/uts/formhandler_TimeFieldTest.php
index a10fdc3..b9b342e 100644
--- a/tests/uts/formhandler_TimeFieldTest.php
+++ b/tests/uts/formhandler_TimeFieldTest.php
@@ -66,11 +66,11 @@ public function timeintervall(): array
     //     define('FH_TIMEFIELD_MINUTE_STEPS', $timeintervall);
     //     $form = new FormHandler();
 
-    //     $this->assertFalse($form->isPosted());
+    //     static::assertFalse($form->isPosted());
 
     //     $form->timeField("Timefield", "timefield", null, false);
 
-    //     $this->assertEmpty($form->getValue("timefield"));
+    //     static::assertEmpty($form->getValue("timefield"));
 
     //     $aExpected = [];
     //     $aExpected[] = 'Timefield:<select name="timefield_hour" id="timefield_hour" size="1">	<option  value="" ></option>';
@@ -80,7 +80,7 @@ public function timeintervall(): array
     //     $aExpected[] = implode("\n\t", $this->getMinutes($timeintervall));
     //     $aExpected[] = '</select>error_timefield';
 
-    //     $this->assertFormFlushContains($form, $aExpected);
+    //     static::assertFormFlushContains($form, $aExpected);
     // }
 
     /**
@@ -92,11 +92,11 @@ public function timeintervall(): array
     //     define('FH_TIMEFIELD_MINUTE_STEPS', $timeintervall);
     //     $form = new FormHandler();
 
-    //     $this->assertFalse($form->isPosted());
+    //     static::assertFalse($form->isPosted());
 
     //     $form->timeField("Timefield", "timefield", null, true);
 
-    //     $this->assertEmpty($form->getValue("timefield"));
+    //     static::assertEmpty($form->getValue("timefield"));
 
     //     $hour = (int)date('H');
     //     $minute = (int)date('i');
@@ -111,7 +111,7 @@ public function timeintervall(): array
     //     $aExpected[] = implode("\n\t", $this->getMinutes($timeintervall, $minute));
     //     $aExpected[] = '</select>error_timefield';
 
-    //     $this->assertFormFlushContains($form, $aExpected);
+    //     static::assertFormFlushContains($form, $aExpected);
     // }
 
     public function test_new_required(): void
@@ -119,11 +119,11 @@ public function test_new_required(): void
         define('FH_TIMEFIELD_SET_CUR_TIME', false);
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->timeField("Timefield", "timefield", null);
 
-        $this->assertEmpty($form->getValue("timefield"));
+        static::assertEmpty($form->getValue("timefield"));
 
         $aExpected = [];
         $aExpected[] = 'Timefield:<select name="timefield_hour" id="timefield_hour" size="1">	<option  value="00"  selected="selected">00</option>';
@@ -132,7 +132,7 @@ public function test_new_required(): void
         $aExpected[] = implode("\n\t", $this->getMinutes(10, 0));
         $aExpected[] = '</select>error_timefield';
 
-        $this->assertFormFlushContains($form, $aExpected);
+        static::assertFormFlushContains($form, $aExpected);
     }
 
     public function test_posted(): void
@@ -143,11 +143,11 @@ public function test_posted(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->timeField("Timefield", "timefield");
 
-        $this->assertEquals("12:34", $form->getValue("timefield"));
+        static::assertEquals("12:34", $form->getValue("timefield"));
     }
 
     public function test_posted_fillvalue_byinvalid(): void
@@ -158,11 +158,11 @@ public function test_posted_fillvalue_byinvalid(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->timeField("Timefield", "timefield", null, false);
 
-        $this->assertEquals("12:30", $form->getValue("timefield"));
+        static::assertEquals("12:30", $form->getValue("timefield"));
 
         $form->setError("timefield", "forcedError");
 
@@ -174,7 +174,7 @@ public function test_posted_fillvalue_byinvalid(): void
         $aExpected[] = implode("\n\t", $this->getMinutes(10, 30));
         $aExpected[] = '</select>error_timefield';
 
-        $this->assertFormFlushContains($form, $aExpected);
+        static::assertFormFlushContains($form, $aExpected);
     }
 
     public function test_validator(): void
@@ -183,15 +183,15 @@ public function test_validator(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->timeField("Timefield", "timefield", FH_NOT_EMPTY);
 
-        $this->assertEmpty($form->getValue("timefield"));
+        static::assertEmpty($form->getValue("timefield"));
 
         $t = $form->catchErrors(false);
 
-        $this->assertEquals(
+        static::assertEquals(
             '<span id="error_timefield" class="error">You did not enter a correct value for this field!</span>',
             $t['timefield']
         );
@@ -202,11 +202,11 @@ public function test_new_format(): void
         define('FH_TIMEFIELD_SET_CUR_TIME', false);
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->timeField("Timefield", "timefield", null, false, 12);
 
-        $this->assertEmpty($form->getValue("timefield"));
+        static::assertEmpty($form->getValue("timefield"));
 
         $aExpected = [];
         $aExpected[] = 'Timefield:<select name="timefield_hour" id="timefield_hour" size="1">	<option  value="" ></option>';
@@ -216,7 +216,7 @@ public function test_new_format(): void
         $aExpected[] = implode("\n\t", $this->getMinutes(10));
         $aExpected[] = '</select>error_timefield';
 
-        $this->assertFormFlushContains($form, $aExpected);
+        static::assertFormFlushContains($form, $aExpected);
     }
 
     public function test_new_format_expected_formaterror(): void
@@ -224,7 +224,7 @@ public function test_new_format_expected_formaterror(): void
         define('FH_TIMEFIELD_SET_CUR_TIME', false);
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->timeField("Timefield", "timefield", null, false, 13);
 
@@ -239,11 +239,11 @@ public function test_new_timefieldsteps($timeintervall): void
         define('FH_TIMEFIELD_MINUTE_STEPS', $timeintervall);
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->timeField("Timefield", "timefield", null, false);
 
-        $this->assertEmpty($form->getValue("timefield"));
+        static::assertEmpty($form->getValue("timefield"));
 
         $aExpected = [];
         $aExpected[] = 'Timefield:<select name="timefield_hour" id="timefield_hour" size="1">	<option  value="" ></option>';
@@ -252,18 +252,18 @@ public function test_new_timefieldsteps($timeintervall): void
         $aExpected[] = implode("\n\t", $this->getMinutes($timeintervall));
         $aExpected[] = '</select>error_timefield';
 
-        $this->assertFormFlushContains($form, $aExpected);
+        static::assertFormFlushContains($form, $aExpected);
     }
 
     public function test_new_extra(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->timeField("Timefield", "timefield", null, false, null, 'data-old="123"');
 
-        $this->assertEmpty($form->getValue("timefield"));
+        static::assertEmpty($form->getValue("timefield"));
 
         $aExpected = [];
         $aExpected[] = 'Timefield:<select name="timefield_hour" id="timefield_hour" size="1" data-old="123">	<option  value="" ></option>';
@@ -272,6 +272,6 @@ public function test_new_extra(): void
         $aExpected[] = implode("\n\t", $this->getMinutes(10));
         $aExpected[] = '</select>error_timefield';
 
-        $this->assertFormFlushContains($form, $aExpected);
+        static::assertFormFlushContains($form, $aExpected);
     }
 };
diff --git a/tests/uts/formhandler_UploadFieldTest.php b/tests/uts/formhandler_UploadFieldTest.php
index c88e1e9..1302ee3 100644
--- a/tests/uts/formhandler_UploadFieldTest.php
+++ b/tests/uts/formhandler_UploadFieldTest.php
@@ -40,13 +40,13 @@ public function test_new(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->uploadField("Uploadfield", "uploadfield");
 
-        $this->assertEmpty($form->getValue("uploadfield"));
+        static::assertEmpty($form->getValue("uploadfield"));
 
-        $this->assertFormFlushContains($form, ['Uploadfield:<input type="file" name="uploadfield" id="uploadfield" onchange="fh_checkUpload(this, \'jpg jpeg png gif doc txt bmp tif tiff pdf\', \'Only the following extensions are allowed: %s.\')"  />error_uploadfield']);
+        static::assertFormFlushContains($form, ['Uploadfield:<input type="file" name="uploadfield" id="uploadfield" onchange="fh_checkUpload(this, \'jpg jpeg png gif doc txt bmp tif tiff pdf\', \'Only the following extensions are allowed: %s.\')"  />error_uploadfield']);
     }
 
     public function test_new_config(): void
@@ -58,13 +58,13 @@ public function test_new_config(): void
 
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->uploadField("Uploadfield", "uploadfield", $config);
 
-        $this->assertEmpty($form->getValue("uploadfield"));
+        static::assertEmpty($form->getValue("uploadfield"));
 
-        $this->assertFormFlushContains($form, ['Uploadfield:<input type="file" name="uploadfield" id="uploadfield" onchange="fh_checkUpload(this, \'jpg jpeg jpe\', \'Only the following extensions are allowed: %s.\')"  />error_uploadfield']);
+        static::assertFormFlushContains($form, ['Uploadfield:<input type="file" name="uploadfield" id="uploadfield" onchange="fh_checkUpload(this, \'jpg jpeg jpe\', \'Only the following extensions are allowed: %s.\')"  />error_uploadfield']);
     }
 
     public function test_posted(): void
@@ -88,21 +88,21 @@ public function test_posted(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->uploadField("Uploadfield", "uploadfield", $config);
 
-        $this->assertTrue($form->isUploaded("uploadfield"));
-        $this->assertEquals("uploaded.jpg", $form->getValue("uploadfield"));
+        static::assertTrue($form->isUploaded("uploadfield"));
+        static::assertEquals("uploaded.jpg", $form->getValue("uploadfield"));
 
         $data  = $form->GetFileInfo("uploadfield");
 
-        $this->assertEquals($_FILES['uploadfield'], $data);
+        static::assertEquals($_FILES['uploadfield'], $data);
 
         $this->setPrivateProperty($form, "_unittestmode", true);
-        $this->assertFlush($form);
+        static::assertFlush($form);
 
-        $this->assertTrue(unlink("{$this->_tempPath}/uploaded.jpg"));
+        static::assertTrue(unlink("{$this->_tempPath}/uploaded.jpg"));
     }
 
     public function test_posted_failure_size(): void
@@ -127,20 +127,20 @@ public function test_posted_failure_size(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->uploadField("Uploadfield", "uploadfield", $config);
 
-        $this->assertTrue($form->isUploaded("uploadfield"));
-        $this->assertEquals("uploaded.jpg", $form->getValue("uploadfield"));
+        static::assertTrue($form->isUploaded("uploadfield"));
+        static::assertEquals("uploaded.jpg", $form->getValue("uploadfield"));
 
         $data  = $form->GetFileInfo("uploadfield");
 
-        $this->assertEquals($_FILES['uploadfield'], $data);
+        static::assertEquals($_FILES['uploadfield'], $data);
 
         $this->setPrivateProperty($form, "_unittestmode", true);
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Uploadfield:<input type="file" name="uploadfield" id="uploadfield" onchange="fh_checkUpload(this, \'jpg jpeg jpe\', \'Only the following extensions are allowed: %s.\')"  class="error" />error_uploadfield',
             '<span id="error_uploadfield" class="error">Maximum file size of 0.1 kb exceeded</span>'
         ]);
@@ -167,20 +167,20 @@ public function test_posted_failure_mime(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->uploadField("Uploadfield", "uploadfield", $config);
 
-        $this->assertTrue($form->isUploaded("uploadfield"));
-        //$this->assertEquals($_FILES['uploadfield']['name'], $form->getValue("uploadfield"));
+        static::assertTrue($form->isUploaded("uploadfield"));
+        //static::assertEquals($_FILES['uploadfield']['name'], $form->getValue("uploadfield"));
 
         $data  = $form->GetFileInfo("uploadfield");
 
-        $this->assertEquals($_FILES['uploadfield'], $data);
+        static::assertEquals($_FILES['uploadfield'], $data);
 
         $this->setPrivateProperty($form, "_unittestmode", true);
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Uploadfield:<input type="file" name="uploadfield" id="uploadfield" onchange="fh_checkUpload(this, \'php\', \'Only the following extensions are allowed: %s.\')"  class="error" />error_uploadfield',
             '<span id="error_uploadfield" class="error">The uploaded file is of an invalid file type!</span>'
         ]);
@@ -207,20 +207,20 @@ public function test_posted_failure_extension(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->uploadField("Uploadfield", "uploadfield", $config);
 
-        $this->assertTrue($form->isUploaded("uploadfield"));
-        //$this->assertEquals($_FILES['uploadfield']['name'], $form->getValue("uploadfield"));
+        static::assertTrue($form->isUploaded("uploadfield"));
+        //static::assertEquals($_FILES['uploadfield']['name'], $form->getValue("uploadfield"));
 
         $data  = $form->GetFileInfo("uploadfield");
 
-        $this->assertEquals($_FILES['uploadfield'], $data);
+        static::assertEquals($_FILES['uploadfield'], $data);
 
         $this->setPrivateProperty($form, "_unittestmode", true);
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Uploadfield:<input type="file" name="uploadfield" id="uploadfield" onchange="fh_checkUpload(this, \'txt\', \'Only the following extensions are allowed: %s.\')"  class="error" />error_uploadfield',
             '<span id="error_uploadfield" class="error">Only the following extensions are allowed: txt.</span>'
         ]);
@@ -249,20 +249,20 @@ public function test_posted_failure_width(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->uploadField("Uploadfield", "uploadfield", $config);
 
-        $this->assertTrue($form->isUploaded("uploadfield"));
-        $this->assertEquals("uploaded.jpg", $form->getValue("uploadfield"));
+        static::assertTrue($form->isUploaded("uploadfield"));
+        static::assertEquals("uploaded.jpg", $form->getValue("uploadfield"));
 
         $data  = $form->GetFileInfo("uploadfield");
 
-        $this->assertEquals($_FILES['uploadfield'], $data);
+        static::assertEquals($_FILES['uploadfield'], $data);
 
         $this->setPrivateProperty($form, "_unittestmode", true);
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Uploadfield:<input type="file" name="uploadfield" id="uploadfield" onchange="fh_checkUpload(this, \'jpg jpeg jpe\', \'Only the following extensions are allowed: %s.\')"  class="error" />error_uploadfield',
             '<span id="error_uploadfield" class="error">The dimension of the image can be 100 x 100 or less. The uploaded file has a dimension of 291 x 139!</span>'
         ]);
@@ -271,7 +271,7 @@ public function test_posted_failure_width(): void
     public function test_posted_failure_override(): void
     {
         // copy src to uploadfolder
-        $this->assertTrue(copy(dirname(__FILE__) . "/test.jpg", "{$this->_tempPath}/uploaded.jpg"));
+        static::assertTrue(copy(dirname(__FILE__) . "/test.jpg", "{$this->_tempPath}/uploaded.jpg"));
 
         $_POST['FormHandler_submit'] = "1";
         $_FILES = [
@@ -292,25 +292,25 @@ public function test_posted_failure_override(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->uploadField("Uploadfield", "uploadfield", $config);
 
-        $this->assertTrue($form->isUploaded("uploadfield"));
-        $this->assertEquals("uploaded.jpg", $form->getValue("uploadfield"));
+        static::assertTrue($form->isUploaded("uploadfield"));
+        static::assertEquals("uploaded.jpg", $form->getValue("uploadfield"));
 
         $data  = $form->GetFileInfo("uploadfield");
 
-        $this->assertEquals($_FILES['uploadfield'], $data);
+        static::assertEquals($_FILES['uploadfield'], $data);
 
         $this->setPrivateProperty($form, "_unittestmode", true);
-        $this->assertFormFlushContains($form, '<span id="error_uploadfield" class="error">The file you tried to upload already exists!</span>');
+        static::assertFormFlushContains($form, '<span id="error_uploadfield" class="error">The file you tried to upload already exists!</span>');
     }
 
     public function test_posted_rename(): void
     {
         // copy src to uploadfolder
-        $this->assertTrue(copy(dirname(__FILE__) . "/test.jpg", "{$this->_tempPath}/uploaded.jpg"));
+        static::assertTrue(copy(dirname(__FILE__) . "/test.jpg", "{$this->_tempPath}/uploaded.jpg"));
 
         $_POST['FormHandler_submit'] = "1";
         $_FILES = [
@@ -332,28 +332,28 @@ public function test_posted_rename(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->uploadField("Uploadfield", "uploadfield", $config);
 
-        $this->assertTrue($form->isUploaded("uploadfield"));
-        $this->assertEquals("uploaded(1).jpg", $form->getValue("uploadfield"));
+        static::assertTrue($form->isUploaded("uploadfield"));
+        static::assertEquals("uploaded(1).jpg", $form->getValue("uploadfield"));
 
         $data  = $form->GetFileInfo("uploadfield");
 
-        $this->assertEquals($_FILES['uploadfield'], $data);
+        static::assertEquals($_FILES['uploadfield'], $data);
 
         $this->setPrivateProperty($form, "_unittestmode", true);
-        $this->assertFlush($form);
+        static::assertFlush($form);
 
-        $this->assertTrue(unlink("{$this->_tempPath}/uploaded.jpg"));
-        $this->assertTrue(unlink("{$this->_tempPath}/uploaded(1).jpg"));
+        static::assertTrue(unlink("{$this->_tempPath}/uploaded.jpg"));
+        static::assertTrue(unlink("{$this->_tempPath}/uploaded(1).jpg"));
     }
 
     public function test_posted_override(): void
     {
         // copy src to uploadfolder
-        $this->assertTrue(copy(dirname(__FILE__) . "/test.jpg", "{$this->_tempPath}/uploaded.jpg"));
+        static::assertTrue(copy(dirname(__FILE__) . "/test.jpg", "{$this->_tempPath}/uploaded.jpg"));
 
         $_POST['FormHandler_submit'] = "1";
         $_FILES = [
@@ -375,21 +375,21 @@ public function test_posted_override(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->uploadField("Uploadfield", "uploadfield", $config);
 
-        $this->assertTrue($form->isUploaded("uploadfield"));
-        $this->assertEquals("uploaded.jpg", $form->getValue("uploadfield"));
+        static::assertTrue($form->isUploaded("uploadfield"));
+        static::assertEquals("uploaded.jpg", $form->getValue("uploadfield"));
 
         $data  = $form->GetFileInfo("uploadfield");
 
-        $this->assertEquals($_FILES['uploadfield'], $data);
+        static::assertEquals($_FILES['uploadfield'], $data);
 
         $this->setPrivateProperty($form, "_unittestmode", true);
-        $this->assertFlush($form);
+        static::assertFlush($form);
 
-        $this->assertTrue(unlink("{$this->_tempPath}/uploaded.jpg"));
+        static::assertTrue(unlink("{$this->_tempPath}/uploaded.jpg"));
     }
 
     public function test_posted_fillvalue_byinvalid(): void
@@ -413,20 +413,20 @@ public function test_posted_fillvalue_byinvalid(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->uploadField("Uploadfield", "uploadfield", $config);
         $form->textField("TextForFailure", "textforfailure");
 
-        $this->assertTrue($form->isUploaded("uploadfield"));
+        static::assertTrue($form->isUploaded("uploadfield"));
 
         $data  = $form->GetFileInfo("uploadfield");
 
-        $this->assertEquals($_FILES['uploadfield'], $data);
+        static::assertEquals($_FILES['uploadfield'], $data);
 
         $form->setError("textforfailure", "isfails");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Uploadfield:<input type="file" name="uploadfield" id="uploadfield" onchange="fh_checkUpload(this, \'jpg jpeg jpe\', \'Only the following extensions are allowed: %s.\')"  class="error" />error_uploadfield',
             "<span id=\"error_uploadfield\" class=\"error\">Because the form isn't valid the file <b>test.jpg</b> has to be selected again if you want to send it with this form!<br />"
         ]);
@@ -453,15 +453,15 @@ public function test_required(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->uploadField("Uploadfield", "uploadfield", $config, FH_NOT_EMPTY);
 
-        $this->assertEmpty($form->getValue("uploadfield"));
+        static::assertEmpty($form->getValue("uploadfield"));
 
         $t = $form->catchErrors(false);
 
-        $this->assertEquals(
+        static::assertEquals(
             '<span id="error_uploadfield" class="error">You did not enter a correct value for this field!</span>',
             $t['uploadfield']
         );
@@ -471,13 +471,13 @@ public function test_new_extra(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->uploadField("Uploadfield", "uploadfield", array(), null, 'data-old="123"');
 
-        $this->assertEmpty($form->getValue("uploadfield"));
+        static::assertEmpty($form->getValue("uploadfield"));
 
-        $this->assertFormFlushContains($form, ['Uploadfield:<input type="file" name="uploadfield" id="uploadfield" onchange="fh_checkUpload(this, \'jpg jpeg png gif doc txt bmp tif tiff pdf\', \'Only the following extensions are allowed: %s.\')" data-old="123" />error_uploadfield']);
+        static::assertFormFlushContains($form, ['Uploadfield:<input type="file" name="uploadfield" id="uploadfield" onchange="fh_checkUpload(this, \'jpg jpeg png gif doc txt bmp tif tiff pdf\', \'Only the following extensions are allowed: %s.\')" data-old="123" />error_uploadfield']);
     }
 
     public function test_resizeImage(): void
@@ -501,27 +501,27 @@ public function test_resizeImage(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->uploadField("Uploadfield", "uploadfield", $config);
 
-        $this->assertTrue($form->isUploaded("uploadfield"));
+        static::assertTrue($form->isUploaded("uploadfield"));
 
         $data  = $form->GetFileInfo("uploadfield");
 
-        $this->assertEquals($_FILES['uploadfield'], $data);
+        static::assertEquals($_FILES['uploadfield'], $data);
 
         $form->resizeImage("uploadfield", $this->_tempPath . "/resize" . $form->getValue("uploadfield"), 30, 30);
 
         $this->setPrivateProperty($form, "_unittestmode", true);
-        $this->assertFlush($form);
+        static::assertFlush($form);
 
         $image_info = getimagesize("{$this->_tempPath}/resizeuploaded.jpg");
 
-        $this->assertEquals(30, $image_info[0]);
+        static::assertEquals(30, $image_info[0]);
 
-        $this->assertTrue(unlink("{$this->_tempPath}/uploaded.jpg"));
-        $this->assertTrue(unlink("{$this->_tempPath}/resizeuploaded.jpg"));
+        static::assertTrue(unlink("{$this->_tempPath}/uploaded.jpg"));
+        static::assertTrue(unlink("{$this->_tempPath}/resizeuploaded.jpg"));
     }
 
     public function test_mergeImage(): void
@@ -545,20 +545,20 @@ public function test_mergeImage(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->uploadField("Uploadfield", "uploadfield", $config);
 
-        $this->assertTrue($form->isUploaded("uploadfield"));
+        static::assertTrue($form->isUploaded("uploadfield"));
 
         $data = $form->GetFileInfo("uploadfield");
 
-        $this->assertEquals($_FILES['uploadfield'], $data);
+        static::assertEquals($_FILES['uploadfield'], $data);
 
         $form->mergeImage("uploadfield", dirname(__FILE__) . "/mergetext.png");
 
         $this->setPrivateProperty($form, "_unittestmode", true);
-        $this->assertFlush($form);
+        static::assertFlush($form);
 
         $filesize = filesize("{$this->_tempPath}/uploadedandmerged.jpg");
         $image_info = getimagesize("{$this->_tempPath}/uploadedandmerged.jpg");
@@ -567,17 +567,17 @@ public function test_mergeImage(): void
         $filesize_orig = filesize($_FILES['uploadfield']['tmp_name']);
         $image_info_orig = getimagesize($_FILES['uploadfield']['tmp_name']);
 
-        $this->assertNotEquals($filesize_orig, $filesize);
-        $this->assertEquals($image_info_orig, $image_info);
+        static::assertNotEquals($filesize_orig, $filesize);
+        static::assertEquals($image_info_orig, $image_info);
 
-        $this->assertTrue(unlink("{$this->_tempPath}/uploadedandmerged.jpg"));
+        static::assertTrue(unlink("{$this->_tempPath}/uploadedandmerged.jpg"));
     }
 
     public function testIsUploaded_expectedError(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isUploaded('upload'));
+        static::assertFalse($form->isUploaded('upload'));
 
         $this->assertTriggertError('Error, the uploadfield "upload" does not exists!', E_USER_NOTICE);
     }
@@ -588,7 +588,7 @@ public function testIsUploaded_expectedError2(): void
 
         $form->textField("Upload", "upload");
 
-        $this->assertFalse($form->isUploaded('upload'));
+        static::assertFalse($form->isUploaded('upload'));
 
         $this->assertTriggertError('Error, the field "upload" is not an uploadfield!', E_USER_NOTICE);
     }
@@ -597,7 +597,7 @@ public function testGetFileInfo_expectedError(): void
     {
         $form = new FormHandler();
 
-        $this->assertCount(0, $form->getFileInfo('upload'));
+        static::assertCount(0, $form->getFileInfo('upload'));
         $this->assertTriggertError('Error, the uploadfield "upload" does not exists!', E_USER_NOTICE);
     }
     
@@ -607,7 +607,7 @@ public function testGetFileInfo_expectedError2(): void
 
         $form->textField("Upload", "upload");
 
-        $this->assertCount(0, $form->getFileInfo('upload'));
+        static::assertCount(0, $form->getFileInfo('upload'));
         $this->assertTriggertError('Error, the field "upload" is not an uploadfield!', E_USER_NOTICE);
     }
 };
diff --git a/tests/uts/formhandler_ViewModeTest.php b/tests/uts/formhandler_ViewModeTest.php
index ac6a7b8..b7911b7 100644
--- a/tests/uts/formhandler_ViewModeTest.php
+++ b/tests/uts/formhandler_ViewModeTest.php
@@ -11,18 +11,18 @@ public function test(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->textField("Textfield", "textfield");
         $form->textField("Textfield2", "textfield2");
 
-        $this->assertFalse($form->isViewMode());
+        static::assertFalse($form->isViewMode());
 
         $form->enableViewMode();
 
-        $this->assertTrue($form->isViewMode());
+        static::assertTrue($form->isViewMode());
 
-        $this->assertFormFlushContains($form, ['Textfield:textvalueerror_textfieldTextfield2:error_textfield2']);
+        static::assertFormFlushContains($form, ['Textfield:textvalueerror_textfieldTextfield2:error_textfield2']);
     }
 
     public function test_fieldViewMode(): void
@@ -33,22 +33,22 @@ public function test_fieldViewMode(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->textField("Textfield", "textfield");
         $form->textField("Textfield2", "textfield2");
 
-        $this->assertFalse($form->isFieldViewMode("textfield"));
-        $this->assertFalse($form->isFieldViewMode("textfield2"));
+        static::assertFalse($form->isFieldViewMode("textfield"));
+        static::assertFalse($form->isFieldViewMode("textfield2"));
 
         $form->setFieldViewMode("textfield");
 
-        $this->assertTrue($form->isFieldViewMode("textfield"));
-        $this->assertFalse($form->isFieldViewMode("textfield2"));
+        static::assertTrue($form->isFieldViewMode("textfield"));
+        static::assertFalse($form->isFieldViewMode("textfield2"));
 
         $form->setError("textfield", "forcedError");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'Textfield:textvalueerror_textfield<span id="error_textfield" class="error">forcedError</span>',
             'Textfield2:<input type="text" name="textfield2" id="textfield2" value="textvalue2" size="20" />error_textfield2'
         ]);
@@ -61,7 +61,7 @@ public function test_fieldViewMode_error_fieldNotExist(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->textField("Textfield", "textfield");
 
@@ -77,7 +77,7 @@ public function test_fieldViewMode_error_NotAField(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->textField("Textfield", "textfield");
 
diff --git a/tests/uts/formhandler_jsDateFieldTest.php b/tests/uts/formhandler_jsDateFieldTest.php
index 92ca7a2..9876f3f 100644
--- a/tests/uts/formhandler_jsDateFieldTest.php
+++ b/tests/uts/formhandler_jsDateFieldTest.php
@@ -8,7 +8,7 @@ public function test_new(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->jsDateField("Datefield", "datefield");
 
@@ -16,7 +16,7 @@ public function test_new(): void
         $disableDate1 = $year - 91;
         $disableDate2 = $year + 1;
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'FHTML/js/calendar_popup.js',
             'document.write(getCalendarStyles());',
             'function getDateString( fldForm, fldYear, fldMonth, fldDay ) {',
@@ -50,7 +50,7 @@ public function test_useDropdown(): void
         define('FH_JSCALENDARPOPUP_USE_DROPDOWN', true);
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->jsDateField("Datefield", "datefield");
 
@@ -58,7 +58,7 @@ public function test_useDropdown(): void
         $disableDate1 = $year - 91;
         $disableDate2 = $year + 1;
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'FHTML/js/calendar_popup.js',
             'document.write(getCalendarStyles());',
             'function getDateString( fldForm, fldYear, fldMonth, fldDay ) {',
@@ -93,7 +93,7 @@ public function test_startday(): void
         define('FH_JSCALENDARPOPUP_STARTDAY', 0);
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->jsDateField("Datefield", "datefield");
 
@@ -101,7 +101,7 @@ public function test_startday(): void
         $disableDate1 = $year - 91;
         $disableDate2 = $year + 1;
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'FHTML/js/calendar_popup.js',
             'document.write(getCalendarStyles());',
             'function getDateString( fldForm, fldYear, fldMonth, fldDay ) {',
diff --git a/tests/uts/formhandler_jsDateTextFieldTest.php b/tests/uts/formhandler_jsDateTextFieldTest.php
index 51e035a..6807d7e 100644
--- a/tests/uts/formhandler_jsDateTextFieldTest.php
+++ b/tests/uts/formhandler_jsDateTextFieldTest.php
@@ -8,13 +8,13 @@ public function test_new(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->jsDateTextField("jsDatejsdatetextfield", "jsdatetextfield");
 
-        $this->assertEmpty($form->getValue("jsdatetextfield"));
+        static::assertEmpty($form->getValue("jsdatetextfield"));
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'FHTML/js/calendar_popup.js',
             'jsDatejsdatetextfield:<input type="text" name="jsdatetextfield" id="jsdatetextfield" value="" size="20" />',
             '<a href=\'javascript:;\' onclick="if( cal_jsdatetextfield ) cal_jsdatetextfield.select(document.forms[\'FormHandler\'].elements[\'jsdatetextfield\'], \'anchor_jsdatetextfield\', \'dd-MM-yyyy\'); return false;"  name=\'anchor_jsdatetextfield\' id=\'anchor_jsdatetextfield\'>',
@@ -42,28 +42,28 @@ public function test_posted(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->jsDateTextField("jsDatejsdatetextfield", "jsdatetextfield");
         $form->jsDateTextField("jsDatejsdatetextfield2", "jsdatetextfield2");
         $form->jsDateTextField("jsDatejsdatetextfield3", "jsdatetextfield3", null, "d.m.Y");
         $form->jsDateTextField("jsDatejsdatetextfield4", "jsdatetextfield4", null, null, true);
 
-        $this->assertEquals("14-04-2020", $form->getValue("jsdatetextfield"));
-        $this->assertEquals("14.04.2020", $form->getValue("jsdatetextfield2"));
-        $this->assertEquals("14.04.2020", $form->getValue("jsdatetextfield3"));
-        $this->assertEquals("14-04-2020", $form->getValue("jsdatetextfield4"));  // already parsed into correct presentation!
+        static::assertEquals("14-04-2020", $form->getValue("jsdatetextfield"));
+        static::assertEquals("14.04.2020", $form->getValue("jsdatetextfield2"));
+        static::assertEquals("14.04.2020", $form->getValue("jsdatetextfield3"));
+        static::assertEquals("14-04-2020", $form->getValue("jsdatetextfield4"));  // already parsed into correct presentation!
 
-        $this->assertEquals([2020, 4, 14], $form->getAsArray("jsdatetextfield"));
-        $this->assertNull($form->getAsArray("jsdatetextfield2"));
+        static::assertEquals([2020, 4, 14], $form->getAsArray("jsdatetextfield"));
+        static::assertNull($form->getAsArray("jsdatetextfield2"));
         $this->assertTriggertError("Value is not a valid date [14.04.2020]", E_USER_ERROR);
-        $this->assertEquals([2020, 4, 14], $form->getAsArray("jsdatetextfield3"));
-        $this->assertEquals([2020, 4, 14], $form->getAsArray("jsdatetextfield4"));
+        static::assertEquals([2020, 4, 14], $form->getAsArray("jsdatetextfield3"));
+        static::assertEquals([2020, 4, 14], $form->getAsArray("jsdatetextfield4"));
 
         $e = $form->catchErrors();
 
-        $this->assertEquals(1, sizeof($e));
-        $this->assertEquals('<span id="error_jsdatetextfield2" class="error">You did not enter a correct value for this field!</span>', $e['jsdatetextfield2']);
+        static::assertEquals(1, sizeof($e));
+        static::assertEquals('<span id="error_jsdatetextfield2" class="error">You did not enter a correct value for this field!</span>', $e['jsdatetextfield2']);
     }
 
     public function test_posted_fillvalue_byinvalid(): void
@@ -73,15 +73,15 @@ public function test_posted_fillvalue_byinvalid(): void
 
         $form = new FormHandler();
 
-        $this->assertTrue($form->isPosted());
+        static::assertTrue($form->isPosted());
 
         $form->jsDateTextField("jsDatejsdatetextfield", "jsdatetextfield");
 
-        $this->assertEquals("14-04-2020", $form->getValue("jsdatetextfield"));
+        static::assertEquals("14-04-2020", $form->getValue("jsdatetextfield"));
 
         $form->setError("jsdatetextfield", "forcedError");
 
-        $this->assertFormFlushContains($form, [
+        static::assertFormFlushContains($form, [
             'jsDatejsdatetextfield:<input type="text" name="jsdatetextfield" id="jsdatetextfield" value="14-04-2020" size="20" class="error" />',
             '<a href=\'javascript:;\' onclick="if( cal_jsdatetextfield ) cal_jsdatetextfield.select(document.forms[\'FormHandler\'].elements[\'jsdatetextfield\'], \'anchor_jsdatetextfield\', \'dd-MM-yyyy\'); return false;"  name=\'anchor_jsdatetextfield\' id=\'anchor_jsdatetextfield\'>',
             'FHTML/images/calendar.gif\' border=\'0\' alt=\'Select Date\' class="error" /></a>',
@@ -102,12 +102,12 @@ public function test_new_extra(): void
     {
         $form = new FormHandler();
 
-        $this->assertFalse($form->isPosted());
+        static::assertFalse($form->isPosted());
 
         $form->jsDateTextField("jsDatejsdatetextfield", "jsdatetextfield", null, null, null, 'data-old="123"');
 
-        $this->assertEmpty($form->getValue("jsdatetextfield"));
+        static::assertEmpty($form->getValue("jsdatetextfield"));
 
-        $this->assertFormFlushContains($form, ['jsDatejsdatetextfield:<input type="text" name="jsdatetextfield" id="jsdatetextfield" value="" size="20"  data-old="123"']);
+        static::assertFormFlushContains($form, ['jsDatejsdatetextfield:<input type="text" name="jsdatetextfield" id="jsdatetextfield" value="" size="20"  data-old="123"']);
     }
 };
diff --git a/tests/uts/helper/FormhandlerTestCase.php b/tests/uts/helper/FormhandlerTestCase.php
index ae85f3c..a4e0b6a 100644
--- a/tests/uts/helper/FormhandlerTestCase.php
+++ b/tests/uts/helper/FormhandlerTestCase.php
@@ -113,7 +113,7 @@ public function executePrivateMethod(FormHandler $form, string $methodName, arra
      * @param string|array $expected
      * @return string HTML for additional validation
      */
-    protected function assertFormFlushContains(FormHandler $form, $expected): string
+    protected static function assertFormFlushContains(FormHandler $form, $expected): string
     {
         $t = (string)$form->flush(true);
         if (is_array($expected))
@@ -122,19 +122,19 @@ protected function assertFormFlushContains(FormHandler $form, $expected): string
             $lastPos = -1;
             foreach ($expected as $e)
             {
-                //$this->assertStringContainsString($e, $t);
+                //static::assertStringContainsString($e, $t);
                 $p = strpos($t, $e);
                 if (!$p)
                 {
-                    $this->fail("missing string:\n{$e}");
+                    static::fail("missing string:\n{$e}");
                 }
 
-                $this->assertGreaterThan($lastPos, $p, "wrong order of strings '{$e}'");
+                static::assertGreaterThan($lastPos, $p, "wrong order of strings '{$e}'");
                 $lastPos = $p;
             }
         }
         else
-            $this->assertStringContainsString($expected, $t);
+            static::assertStringContainsString($expected, $t);
 
         return (string)$t;
     }
@@ -145,9 +145,9 @@ protected function assertFormFlushContains(FormHandler $form, $expected): string
      * @param FormHandler $form
      * @return void
      */
-    protected function assertFlush(FormHandler $form): void
+    protected static function assertFlush(FormHandler $form): void
     {
         $t = $form->flush(true);
-        $this->assertEquals("", $t);
+        static::assertEquals("", $t);
     }
 };
diff --git a/tests/uts/helper/dbFormhandlerTestCase.php b/tests/uts/helper/dbFormhandlerTestCase.php
index 8c3f431..fe2f270 100644
--- a/tests/uts/helper/dbFormhandlerTestCase.php
+++ b/tests/uts/helper/dbFormhandlerTestCase.php
@@ -20,26 +20,26 @@ abstract class dbFormhandlerTestCase extends FormhandlerTestCase
 
     protected function assertSavedId(int $expected): void
     {
-        $this->assertTrue(is_array($this->_expectedResult), "function 'dbFormhandlerTestCase::setCallbackOnSaved' not called");
-        $this->assertTrue(sizeof($this->_expectedResult) > 0, "formhandler don't call callback function");
+        static::assertTrue(is_array($this->_expectedResult), "function 'dbFormhandlerTestCase::setCallbackOnSaved' not called");
+        static::assertTrue(sizeof($this->_expectedResult) > 0, "formhandler don't call callback function");
 
-        $this->assertEquals($expected, $this->_expectedResult['id']);
+        static::assertEquals($expected, $this->_expectedResult['id']);
     }
     protected function assertSavedValue($expected, string $field): void
     {
-        $this->assertTrue(is_array($this->_expectedResult), "function 'dbFormhandlerTestCase::setCallbackOnSaved' not called");
-        $this->assertTrue(sizeof($this->_expectedResult) > 0, "formhandler don't call callback function");
+        static::assertTrue(is_array($this->_expectedResult), "function 'dbFormhandlerTestCase::setCallbackOnSaved' not called");
+        static::assertTrue(sizeof($this->_expectedResult) > 0, "formhandler don't call callback function");
 
-        $this->assertTrue(array_key_exists($field, $this->_expectedResult['values']), "field not saved");
-        $this->assertEquals($expected, $this->_expectedResult['values'][$field]);
+        static::assertTrue(array_key_exists($field, $this->_expectedResult['values']), "field not saved");
+        static::assertEquals($expected, $this->_expectedResult['values'][$field]);
     }
     protected function assertSavedValueEmtpy(string $field): void
     {
-        $this->assertTrue(is_array($this->_expectedResult), "function 'dbFormhandlerTestCase::setCallbackOnSaved' not called");
-        $this->assertTrue(sizeof($this->_expectedResult) > 0, "formhandler don't call callback function");
+        static::assertTrue(is_array($this->_expectedResult), "function 'dbFormhandlerTestCase::setCallbackOnSaved' not called");
+        static::assertTrue(sizeof($this->_expectedResult) > 0, "formhandler don't call callback function");
 
-        $this->assertTrue(array_key_exists($field, $this->_expectedResult['values']), "field not saved");
-        $this->assertEmpty($this->_expectedResult['values'][$field]);
+        static::assertTrue(array_key_exists($field, $this->_expectedResult['values']), "field not saved");
+        static::assertEmpty($this->_expectedResult['values'][$field]);
     }
 
     protected function setUp(): void