var newWindow = null;

function popupWindow(url, width, height) {
	if (newWindow != null && !newWindow.closed) {
		//close the window and call yourself!
		newWindow.close();
		popupWindow(url, width, height);
	} else {
		//creating the window
		config='toolbar=no,location=no,directories=no,status=no,menubar=no,width='+width+',height='+height+',scrollbars=yes,resizable=no';
		newWindow = window.open(url,'newWindow',config);
	}
}