function ajaxFunction(obj)
 {
 var xmlHttp;
 
 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("您的浏览器不支持AJAX！");
         return false;
         }
      }
    }
	
      xmlHttp.onreadystatechange=function()
      {
      
      for(var m=0;m<document.getElementById("city").options.length;m++)
      {
        document.getElementById("city").options.remove(m);   
      }
      
      if(xmlHttp.readyState==4)
      {
         var citylist=xmlHttp.responseText;
         var i,j;
         var t1=citylist.split("|");
         var t2;
         for(i=0;i<t1.length-1;i++)
         {
            t2=t1[i].split(",");
            
            oItem=document.createElement('OPTION');
            oItem.text=t2[1];
            oItem.value=t2[0];
            document.getElementById("city").options.add(oItem);
         }
        
        //document.getElementById("cityi_hf").value= document.getElementById("city_ddl").value;

      }
        
      }
      
    xmlHttp.open("GET","/js/ajax.aspx?shengid="+obj.value,true);
    xmlHttp.send(null);
  
 }