Code to determine the size of the browser window using javascript

<script>
var w=window.innerWidth
|| document.documentElement.clientWidth
|| document.body.clientWidth;

var h=window.innerHeight
|| document.documentElement.clientHeight
|| document.body.clientHeight;

x=document.getElementById("demo");
x.innerHTML="Browser inner window width: " + w + ", height: " + h + "."
</script>