Ajax basic instance returns XML

// Ajax request for the City Data
Function ajaxforget (CN ){
VaR xmlhttp_request = "";
Try {
If (window. activexobject ){
For (VAR I = 5; I --){
Try {
If (I = 2 ){
Xmlhttp_request = new activexobject ("Microsoft. XMLHTTP ");
}
Else {
Xmlhttp_request = new activexobject ("msxml2.xmlhttp." + I + ". 0 ");
}
Break;
}
Catch (e ){
Xmlhttp_request = false;
}
}
}
Else if (window. XMLHttpRequest ){
Xmlhttp_request = new XMLHttpRequest ();
}
}
Catch (e) {xmlhttp_request = false ;}
If (! Xmlhttp_request ){
Alert ("your browser does not support Ajax ");
Return;
}
Xmlhttp_request.open ('get', '../handler/citydata. ashx? Code = '+ CN +' & time = '+ new date (). getmilliseconds (), true );

Xmlhttp_request.setrequestheader ("Content-Type", "text/XML"); // setRequestHeader ("Header", "value ")
Xmlhttp_request.setrequestheader ("charset", "gb2312"); // set the specified header to the provided value. You must call open () before setting any header ()
Xmlhttp_request.send (null );
VaR self = xmlhttp_request; // assign the reference to the temporary variable self
Xmlhttp_request.onreadystatechange = function (){
Thecallback (Self );
};
}

// Ajax callback function
Function thecallback (xmlhttp_request ){
If (xmlhttp_request.readystate = 4 & xmlhttp_request.status = 200 ){
// Bind item
VaR DATA = xmlhttp_request.responsexml;
VaR citys = data. getelementsbytagname ("name ");
VaR CNS = data. getelementsbytagname ("Code ");
VaR listcity = $ ("listcity ");
Listcity. innerhtml = ""; // remove all items first
VaR listp = $ ("listprovince ");
VaR code = listp. Options [listp. selectedindex]. value;
VaR item = new array ();
For (VAR I = 0; I <Citys. length; I ++ ){
If (Citys. length! = 1 & code = CNS [I]. childnodes [0]. Data) continue;
Item [I] = Document. createelement ("option ");
Item [I]. value = Central [I]. childnodes [0]. Data;
Item [I]. innerhtml = citys [I]. childnodes [0]. Data;
Listcity. appendchild (item [I]);
}
// End the bound item
$ ("Txtcode"). value = listcity. Options [0]. value;
}
}