index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="stylesheet" href="style.css"> 
    <title>validated login form</title>
</head>

<body>
    <div class="container">

        <h1 class="lable">User Login</h1>

        <form class="login_form" action="home.html" method="post" name="form" onsubmit="return validated()">
            <div class="font">Email or Phone</div>
            <input type="text" name="email">
            <div id="email_error">please fill up your email or phone</div>

            <div class="font font_2">password</div>
            <input type="password" name="password">
            <div id="pass_error">please fill up your password</div>

            <button type="submit">Login</button>
        </form>

    </div>

    <script type="text/javascript" src="main.js"></script>
</body>
</html>