function termine(url) {
        windowName = "Kalender";
        options  = "";
        options += "toolbar=0,";
        options += "location=0,";
        options += "directories=0,";
        options += "status=0,";
        options += "menubar=0,";
        options += "scrollbars=0,";
        options += "resizable=1,";
        options += "width=450,";
        options += "height=400";
        win = window.open(url, windowName , options);
        if (!win.opener) {
          win.opener = window;
        }
      };