function callogin(kalender)
  {
            switch (kalender) {
    	   	case "trigaspec":
                 fenster =
                 window.open("http://www.uni-mainz.de/FB/Chemie/AK-Noertershaeuser/members/calendars.html?cal=trigaspec");
                 fenster.focus();
    		break;

    		case "collaps":
                 fenster =
                 window.open("http://www.uni-mainz.de/FB/Chemie/AK-Noertershaeuser/members/calendars.html?cal=collaps");
                 fenster.focus();
    	   	break;

    	   	case "spectrap":
                 fenster =
                 window.open("http://www.uni-mainz.de/FB/Chemie/AK-Noertershaeuser/members/calendars.html?cal=spectrap");
                 fenster.focus();
    		break;

    		case "srt":
                 fenster =
                 window.open("http://www.uni-mainz.de/FB/Chemie/AK-Noertershaeuser/members/calendars.html?cal=srt");
                 fenster.focus();
    	   	break;

    	   	case "libelle":
                 fenster =
                 window.open("http://www.uni-mainz.de/FB/Chemie/AK-Noertershaeuser/members/calendars.html?cal=libelle");
                 fenster.focus();
    		break;

    		case "travel":
                 fenster =
                 window.open("http://www.uni-mainz.de/FB/Chemie/AK-Noertershaeuser/members/calendars.html?cal=travel");
                 fenster.focus();
    	   	break;

    	   	case "conferences":
                 fenster =
                 window.open("http://www.uni-mainz.de/FB/Chemie/AK-Noertershaeuser/members/event-calendar.html?cal=conferences");
                 fenster.focus();
    		break;

                 default :
                 fenster =
                 window.open("http://www.uni-mainz.de/FB/Chemie/AK-Noertershaeuser/members/calendars.html");
                 fenster.focus();
	   }






   }