function documentSize() 
{
    var xScroll, yScroll;
    var pageWidth, pageHeight, windowWidth, windowHeight
    if (window.innerHeight && window.scrollMaxY) {
        xScroll = document.body.scrollWidth;
        yScroll = window.innerHeight + window.scrollMaxY;
    } else if (document.body.scrollHeight > document.body.offsetHeight) { // all but Explorer Mac
        xScroll = document.body.scrollWidth;
        yScroll = document.body.scrollHeight;
    } else { // Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari
        xScroll = document.body.offsetWidth;
        yScroll = document.body.offsetHeight;
    }

    if (self.innerHeight) {	// all except Explorer
        windowWidth = self.innerWidth;
        windowHeight = self.innerHeight;
    } else if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode
        windowWidth = document.documentElement.clientWidth;
        windowHeight = document.documentElement.clientHeight;
    } else if (document.body) { // other Explorers
        windowWidth = document.body.clientWidth;
        windowHeight = document.body.clientHeight;
    }

    // for small pages with total height less then height of the viewport
    if (yScroll < windowHeight) {
        pageHeight = windowHeight;
    } else {
        pageHeight = yScroll;
    }

    // for small pages with total width less then width of the viewport
    if (xScroll < windowWidth) {
        pageWidth = windowWidth;
    } else {
        pageWidth = xScroll;
    }
    return { width: pageWidth, height: pageHeight };
}

function pageWidth() 
{
	return window.innerWidth != null? window.innerWidth : document.documentElement && document.documentElement.clientWidth ? document.documentElement.clientWidth : document.body != null ? document.body.clientWidth : null;
} 

function pageHeight() 
{
	return  window.innerHeight != null? window.innerHeight : document.documentElement && document.documentElement.clientHeight ?  document.documentElement.clientHeight : document.body != null? document.body.clientHeight : null;
} 

function posLeft() 
{
	return typeof window.pageXOffset != 'undefined' ? window.pageXOffset :document.documentElement && document.documentElement.scrollLeft ? document.documentElement.scrollLeft : document.body.scrollLeft ? document.body.scrollLeft : 0;
} 

function posTop() 
{
	return typeof window.pageYOffset != 'undefined' ?  window.pageYOffset : document.documentElement && document.documentElement.scrollTop ? document.documentElement.scrollTop : document.body.scrollTop ? document.body.scrollTop : 0;
} 

function posRight() 
{
	return posLeft()+pageWidth();
} 

function posBottom() 
{
    return posTop()+pageHeight();
}