​x
 
<!DOCTYPE html>
<html>
<head>
<style>
#myDIV {
  background-color: coral;
  border: 1px solid;
  padding: 50px;
  color: white;
  font-size: 20px;
}
</style>
</head>
<body>
​
<h2>JavaScript removeEventListener()</h2>
​
<div id="myDIV">
  <p>This div element has an onmousemove event handler that displays a random number every time you move your mouse inside this orange field.</p>
  <p>Click the button to remove the div's event handler.</p>
  <button onclick="removeHandler()" id="myBtn">Remove</button>
</div>
​
<p id="demo"></p>
​
<script>
document.getElementById("myDIV").addEventListener("mousemove", myFunction);
​
function myFunction() {
  document.getElementById("demo").innerHTML = Math.random();
}
​
function removeHandler() {
  document.getElementById("myDIV").removeEventListener("mousemove", myFunction);
}
</script>
​
</body>
</html>
​
​
​