var xmlHttp;
        function createXMLHttpRequest()
        {
            if(window.ActiveXObject)
            {
                xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
            }
            else if(window.XMLHttpRequest)
            {
                xmlHttp=new XMLHttpRequest();
            }            
        }

function onselect3(bigclassid){
	
if(bigclassid==0){
document.getElementById("VOLTAGE").innerHTML="<select name='VOLTAGE'><option value='0' selected>选择二级分类</option></select>";
return;
};

createXMLHttpRequest();
//如果创建对象xmlhttpobj成功
var url="getsubcategory3.asp?bigclassid="+bigclassid;

xmlHttp.open("GET",url,true);
xmlHttp.onreadystatechange=ShowuserErr3;
xmlHttp.setrequestheader("cache-control","no-cache"); 
xmlHttp.setrequestheader("Content-Type","application/x-www-form-urlencoded");
xmlHttp.send(null);
}

 function ShowuserErr3()
        {          
             
            if(xmlHttp.readyState==4)
            {
                if(xmlHttp.status==200)
                {             
                    var html = xmlHttp.responseText;//获得返回值
					document.getElementById("VOLTAGE").innerHTML=html;
                }
				else
				{
					
					document.getElementById("VOLTAGE").innerHTML="不对";
				}
            }
        }