function karten_fenster(b,h,lat,lng)
{
var url = "../gmap/gmap.htm?b="+b+"&"+"h="+h+"&"+"lat=" + lat + "&" + "lng=" +lng;
var parameter="width="+b+",height="+h+",left="+(screen.width-b)/2+",top="+(screen.height-h)/2+",location=no";
var win = window.open('','Karte',parameter);  // erzeugt das Fenster
win.location.href = url;  // lädt im neuen Fenster diesen url
win=null;
return true;
}