简单AJAX 使用

 var xmlHttp;
    function createXMLHttpRequestss() {
     if (window.ActiveXObject) {
      xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
     }else if (window.XMLHttpRequest) {
      xmlHttp = new XMLHttpRequest();
     }
    }
     
     function startRequest(){
     var projectName = document.getElementById("pronameid").value;
     var alarmName = document.getElementById("alarmNameId").value;
      var url = "getAgentNo.action?randcount="+Math.random()+"&code="+document.getElementById("selectId").value+"&alarmName="+alarmName+"&projectName="+projectName+"&skillName="+document.getElementById("skillGroupId").value;
      createXMLHttpRequestss();
         xmlHttp.onreadystatechange = handleStateChange;
      xmlHttp.open("get",url,false);
      xmlHttp.send(null);
     }
    
     function handleStateChange(){
      if(xmlHttp.readyState == 4 ) {
              if(xmlHttp.status == 200) {
               if(xmlHttp.responseText == null || xmlHttp.responseText == ""){
                return;
               }
        var obj =eval('('+ xmlHttp.responseText+')');