var f1 = null;

function popup(url, breite, hoehe){

links = 100;
oben = 100;

if (navigator.platform.indexOf('Win') > -1){
	if (f1 && f1.open && !f1.closed){
		breiteneu = breite + 5;
		hoeheneu = hoehe + 50;
		f1.resizeTo(breiteneu,hoeheneu);
		f1.focus();
		f1.document.close();
		f1 = window.open(url, "fenster", "width="+breite+",height="+hoehe+",left="+links+",top="+oben+", resize=yes, scrollbars=no");
		f1.focus();
	}else{
		f1 = window.open(url, "fenster", "width="+breite+",height="+hoehe+",left="+links+",top="+oben+", resize=yes, scrollbars=no");
		f1.focus();
		}
}else{
		f1 = window.open(url, "fenster", "width="+breite+",height="+hoehe+",left="+links+",top="+oben+", resize=yes, scrollbars=no");
		f1.focus();
		}
}