function sv_AjaxFunction(serverUrl, evalScript, isAsync){
    var xmlHttp = null;
    try{// Firefox, Opera 8.0+, Safari
      xmlHttp = new XMLHttpRequest();
    }catch (e){// Internet Explorer
      try{
        xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
      }catch (e){
        try{
          xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
        }catch (e){
          alert("Your browser does not support AJAX!");
          return "";
        }
      }
    }
    xmlHttp.onreadystatechange=function(){
      if(xmlHttp.readyState==4){
        //FROM EXAMPLE -- document.myForm.time.value=xmlHttp.responseText;
        eval(evalScript);
      }
    }
    xmlHttp.open("GET", serverUrl, isAsync);
    xmlHttp.send(null);
    if (!isAsync)
      return xmlHttp.responseText;
    return "nothing";
}