Cross browser function to identify viewport size

universal viewport

function viewport(){
    var w=window,d=document,e=d.documentElement,g=d.getElementsByTagName('body')[0];

    // Standards compliant browsers (mozilla/netscape/opera/IE7): window.innerWidth & window.innerHeight
    
    // IE6 in standards compliant mode: documentElement.clientWidth & documentElement.clientHeight

    // Older IE6
    // document.getElementsByTagName('body')[0].clientWidth &
    // document.getElementsByTagName('body')[0].clientHeight

    return {
        x: w.innerWidth||e.clientWidth||g.clientWidth,
        y: w.innerHeight||e.clientHeight||g.clientHeight
    }
}