function umfrage() {
	var param, w=502, h=750;
	if (navigator.userAgent.indexOf("MSIE")<0) {
		var dx = Math.round((screen.width/2)-(w/2));
		var dy = Math.round((screen.height/2)-(h/2));
		param = "innerWidth=" + w + ",innerHeight=" + h + ",screenX=" + dx + ",screenY=" + dy;
	}
	else {
		w += 16;
		h += 3;
		param = "width=" + w + ",height=" + h;
	}
	window.open("http://www.falke.de/umfrage/index.php", "_blank", param+",resizable=yes,scrollbars=yes,dependent=yes");
}