// JavaScript Document
function _getViewportRect(){
	
	var viewportwidth,viewportheight;	
	
		// the more standards compliant browsers (mozilla/netscape/opera/IE7) use window.innerWidth and window.innerHeight	
	if (typeof window.innerWidth != 'undefined'){
		viewportwidth = window.innerWidth,
		viewportheight = window.innerHeight
	}else if (typeof document.documentElement != 'undefined' && typeof document.documentElement.clientWidth != 'undefined' && document.documentElement.clientWidth != 0){
		// IE6 in standards compliant mode (i.e. with a valid doctype as the first line in the document)
		viewportwidth = document.documentElement.clientWidth,
		viewportheight = document.documentElement.clientHeight
	}else{
		// older versions of IE
		viewportwidth = document.getElementsByTagName('body')[0].clientWidth,
		viewportheight = document.getElementsByTagName('body')[0].clientHeight
	}
	
	return {width:viewportwidth,height:viewportheight};
}