Example

HTML

<!-- Learn about this code on MDN: https://developer.mozilla.org/en-US/docs/Web/API/Document/createElement -->

<!DOCTYPE html>
<html>
<head>
  <title>||Working with elements||</title>
</head>
<body>
  <div id="div1">The text above has been created dynamically.</div>
</body>
</html>

JavaScript

document.body.onload = addElement;

function addElement () { 
	var myImage = new Image(400, 100);
	myImage.src = 'https://www.google.com/logos/doodles/2017/holidays-2017-day-2-5240850203279360-s.png';
  myImage.id = "myImageId";
  myImage.onclick = myVerySpecialFunction();
  var tmp = "myVerySpecialFunctionAnswer()";
  document.body.appendChild(myImage);
  document.getElementById("myImageId").setAttribute("onclick", tmp);
}
function myVerySpecialFunction() {
	alert("Knock-knock!");
}
function myVerySpecialFunctionAnswer() {
	alert("Who is there!?");
}