JS Events

<!DOCTYPE html>
<html>
<body>

<p>This example uses the HTML DOM to assign an "onload" event to an iframe element.</p>

<iframe id="myFrame" src="https://www.closetag.com/"></iframe>

<p id="demo"></p>

<script>
document.getElementById("myFrame").onload = function() {myFunction()};

function myFunction() {
  document.getElementById("demo").innerHTML = "Iframe is loaded.";
}
</script>

</body>
</html>