The code copy is as follows:
<script>
//Get page height
var yScroll = (document.documentElement.clientHeight >document.documentElement.clientHeight) ? document.documentElement.scrollHeight : document.documentElement.clientHeight;
alert(yScroll)
//Get page width
var xScroll=(document.documentElement.scrollWidth>document.documentElement.clientWidth) ? document.documentElement.scrollWidth : document.documentElement.scrollWidth;
alert(xScroll)
</script>