index.js

let cont = document.getElementById("contactbox");

function setup() {
  cont.style.display = "block";
}
function closediv() {
  cont.style.display = "none";
}

let sourcetext = document.getElementById("closevw");

setTimeout(function closeview() {
  sourcetext.style.display = "block";
}, 9000);

function closesource() {
  sourcetext.style.display = "none";
}

// div animation
function reveal() {
  let reveals = document.querySelectorAll(".reveal");

  for (let i = 0; i < reveals.length; i++) {
    let windowHeight = window.innerHeight;
    let elementTop = reveals[i].getBoundingClientRect().top;
    let elementVisible = 15;

    if (elementTop < windowHeight - elementVisible) {
      reveals[i].classList.add("active");
    } else {
      reveals[i].classList.remove("active");
    }
  }
}

window.addEventListener("scroll", reveal);