<!DOCTYPE html>
<html>
<body>
<p>This example uses the addEventListener() method on the window object.</p>
<p>Try resizing this browser window to trigger the "resize" event handler.</p>
<p id="demo"></p>
<script>
window.addEventListener("resize", function(){
document.getElementById("demo").innerHTML = Math.random();
});
</script>
</body>
</html>