function openPopup(url, width, height)
{
	var left = (screen.width - width) / 2;
	var top = (screen.height - height) / 2;
	window.open(url,"","menubar=no, status=no, scrollbars=yes, menubar=no, width=" + width + ", height=" + height + ", left=" + left + ", top=" + top);
}