/// <reference path="jquery-1.3.2.js" />

function getViewPortHeight() {

    var viewportheight
    // the more standards compliant browsers (mozilla/netscape/opera/IE7) use window.innerWidth and window.innerHeight

    if (typeof window.innerWidth != 'undefined') {
        viewportheight = window.innerHeight
    }

    // IE6 in standards compliant mode (i.e. with a valid doctype as the first line in the document)

    else if (typeof document.documentElement != 'undefined'
                && typeof document.documentElement.clientWidth !=
                    'undefined' && document.documentElement.clientWidth != 0) {
        viewportheight = document.documentElement.clientHeight
    }

    // older versions of IE

    else {
        viewportheight = document.getElementsByTagName('body')[0].clientHeight
    }

    return viewportheight;
}