function centerpopup(URL,width,height){
				if (parseInt(navigator.appVersion) >= 3){
					if (navigator.appName == "Netscape" && parseInt(navigator.appVersion)<5){
						var tools = new Packages.java.awt.Toolkit.getDefaultToolkit();
						screen=tools.getScreenSize();
					}
					x = screen.width;
					y = screen.height;
				}
				window.open(URL,"dummy","top=" + parseInt(y/2-height/2-16) + ",left=" + parseInt(x/2-width/2-5) + ",scrollbars=yes,width=" + width + ",height=" + height);
			}