Code
'<div id="popupInner">' +
            '<div id="popupTitleBar">' +
                '<div id="popupTitle"></div>' +
                '<div id="popupControls">' +
                    '<img src="subModal/close.gif" onclick="hidePopWin(false);" id="popCloseBox" />' +
                '</div>' +
            '</div>' +
            '<iframe src="'+ gDefaultPage +'" style="width:100%;height:100%;background-color:transparent;" scrolling="auto" frameborder="0" allowtransparency="true" id="popupFrame" name="popupFrame" width="100%" height="100%"></iframe>' +
        '</div>';

Code
function getViewportHeight() {
    if (window.innerHeight!=window.undefined) return window.innerHeight;
    if (document.compatMode=='CSS1Compat') return document.documentElement.clientHeight;
    if (document.body) return document.body.clientHeight; 

    return window.undefined; 
}
function getViewportWidth() {
    var offset = 17;
    var width = null;
    if (window.innerWidth!=window.undefined) return window.innerWidth; 
    if (document.compatMode=='CSS1Compat') return document.documentElement.clientWidth; 
    if (document.body) return document.body.clientWidth; 
}

/**
 * Gets the real scroll top
 */
function getScrollTop() {
    if (self.pageYOffset) // all except Explorer
    {
        return self.pageYOffset;
    }
    else if (document.documentElement && document.documentElement.scrollTop)
        // Explorer 6 Strict
    {
        return document.documentElement.scrollTop;
    }
    else if (document.body) // all other Explorers
    {
        return document.body.scrollTop;
    }
}
function getScrollLeft() {
    if (self.pageXOffset) // all except Explorer
    {
        return self.pageXOffset;
    }
    else if (document.documentElement && document.documentElement.scrollLeft)
        // Explorer 6 Strict
    {
        return document.documentElement.scrollLeft;
    }
    else if (document.body) // all other Explorers
    {
        return document.body.scrollLeft;
    }
}