function wop(nr)
        {
        var url;
        switch (nr)
               {
               case 1: url = new String("csch.html");break;
               case 2: url = new String("asch.html");break;
               case 3: url = new String("wag.html");break;
               case 4: url = new String("bra.html");break;
               case 5: url = new String("doer.html");break;
               case 6: url = new String("mer.html");break;
               case 7: url = new String("zyl.html");break;
               case 8: url = new String("beh.html");break;
               case 9: url = new String("may.html");break;
               case 10: url = new String("klu.html");break;
               case 11: url = new String("ssch.html");break;
               default: url = new String("error");break;
               }
        var form="width=450,height=370,screenx=0,screeny=0,locationbar=no,menubar=no,resizable=no,status=no";
        window.open(url,url.replace(".html",""),form);
        }