var xmlHttp,obj,isIE;
function createXMLHTTP()
{

    if(window.XMLHttpRequest)
    {
        xmlHttp=new XMLHttpRequest();//mozilla浏览器
        isIE=false;
    }
    else if(window.ActiveXObject)
    {
        try
        {
            xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");//IE老版本
            isIE=true;
        }
        catch(e)
        {}
        try
        {
            xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");//IE新版本
             isIE=true;
        }
        catch(e)
        {}
        if(!xmlHttp)
        {
            window.alert("不能创建XMLHttpRequest对象实例！");
            return false;
        }
    }
    
}

function CallServer(url,value)
{
    createXMLHTTP();
    xmlHttp.open("post",url,false);
    xmlHttp.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
    xmlHttp.send(value);
    if(xmlHttp.readyState==4)
    {
        if(xmlHttp.status==200)
        {
        return xmlHttp.responseXML;
        }
        else
        {
            return "";
        }
    } 
    
}
function callback(obj,xml)
{

    var xmlDoc=xml.documentElement;
    if(xmlDoc == null)
        return;
    var xSel=xmlDoc.getElementsByTagName("select");
    
    for(var i=0;i<xSel.length;i++)
    {
        var xValue=xSel[i].childNodes[0].firstChild.data;
        var xText=xSel[i].childNodes[1].firstChild.data;
        var option=new Option(xText,xValue);
        try
        { 
            obj.options.add(option);
           
        }
        catch(e)
        {
            
        }
    }
 
}
function change_area(val,objid)
{
   var areaid=val;
   var url="/getAreaRoad.aspx";
   var sendxml="type=road&id="+areaid;
   var xml=CallServer(url,sendxml);
   objid.options.length=0;
   callback(objid,xml);
}
function change_road(val,objid)
{
   var roadid=val;
   var url="/getAreaRoad.aspx";
   var sendxml="type=hs&id="+roadid;
   objid.options.length=0;
   var xml=CallServer(url,sendxml);
   objid.options.length=0;
   callback(objid,xml);
}


function LoadTopArea(objid)
{
   var url="/getAreaRoad.aspx";
   var sendxml="type=area&id=0";
   objid.options.length=0;
   var xml=CallServer(url,sendxml);
   objid.options.length=0;
   callback(objid,xml);
}
function LoadDefaultArea(objid)
{
    LoadTopArea(objid);
}

function LoadDefArea(objid)
{
    LoadTopArea(objid);
}