var req = null;
        function erstelleAnfrageobjekt(){
          try{
            req = new XMLHttpRequest();
          }
          catch (e){
            try{
              req = new ActiveXObject("Msxml2.XMLHTTP");
            }
            catch (e){
              try{
                req = new ActiveXObject("Microsoft.XMLHTTP");
              }
              catch (failed){
                req = null;
              }
            }
          }
          if (req == null) {
            alert("An Error occured when trying to initialize XMLHttpRequest!");
            return;
          }
        }

        function erstelleAnfrage (){
          erstelleAnfrageobjekt()

          var jetzt = new Date();

          req.open("GET","ajax/ajax_sec.php?time="+jetzt.getTime(),true);
          req.onreadystatechange=callback;
          req.send(null);
        }

        function callback (){
          if (req.readyState==4 && req.status==200){
            document.getElementById("pic_sec").innerHTML = "<img src=\"images/secur/secgb_"+req.responseText+"c.jpg\" align=\"middle\">";
            document.getElementById("summe").value = req.responseText;
          }
        }