function customWinOpen(url, name, breite, hoehe) 
     {
       links = (screen.width/2)-(breite/2);
       oben = (screen.height/2)-(hoehe/2);
       window.open(url, name,"height="+hoehe+",width="+breite+",status = no,toolbar = no,menubar = no,location = no,resizable = no,titlebar = no,scrollbars = no,fullscreen = no,top ="+oben+",left ="+links);
     }