function getwindowsize() {
	if (navigator.userAgent.indexOf("MSIE") > 0) {
		var sSize = Math.abs(((document.body.clientWidth-770)/2));
		return sSize;
	} else {                                                
		var sSize = Math.abs(((window.outerWidth-770)/2));
		return sSize;
	}
	return;      
}