function openwindow(dateiname, fenstername, breite, hoehe){
	fenster = window.open(dateiname,fenstername,'location=0,toolbar=no,width=' + breite + ',height=' + hoehe + ',directories=no,scrollbars=yes,resize=no,menubar=no,status=no');
	fenster_offen = "true";
	if ( parseInt(navigator.appVersion.substring(0,1)) >= 4 ){
		links = (screen.availWidth - parseInt(breite)) / 2;
		rechts = (screen.availHeight - parseInt(hoehe)) / 2;
		fenster.moveTo( links,rechts-30 );
		fenster.focus();
				
			if ((screen.availWidth - eval(breite)) <=30 ) { fenstername.screenX = 1 };
					};
							return;
				};