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

   } 

newwin.focus();