function popup (url, breite, hoehe)
{
	screenY = 0;
	screenX = 0;
	hwin = open(url,'bilder','toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=no,width=' + breite + ',height=' + hoehe + ',screenX=' + screenX + ',screenY=' + screenY);
}