var ajax = null;
if (window.XMLHttpRequest)
      {ajax = new XMLHttpRequest();}
else if (window.ActiveXObject)
      {ajax = new ActiveXObject("Microsoft.XMLHTTP");}

 
function refresh_div(Div, Seite)
{

      ajax.open("GET", Seite, true);
      ajax.onreadystatechange = function()
      {
            if(ajax.readyState == 4)
      {            document.getElementById(Div).innerHTML = ajax.responseText;}
      }  
      ajax.send(null);
      
}