function Fenster(URL1,URL2,URL3,URL4) { 
	
	var trg;
	
	if (parent.nav) {
		trg = parent;
	} else if (parent.parent.nav) {
		trg = parent.parent;
	}
	trg.nav.location.href=URL1;
	
	if (URL2.indexOf('subnav') !== -1) {
		URL2 = URL2.replace(/subnav/g, "frameset");
	}

	trg.subnav_main.location.href=URL2;
	trg.quicknav.location.href=URL3;
}