Server -  AjaxProcessor.aspx :  
           
           XmlDocument doc = new XmlDocument();
            doc.****  // manipulate data in doc, include Insert, Remove or Replace

            //begin output to client
            Response.Clear();
            Response.Write(doc.InnerXml);
            Response.End();


Client - Ajax

 var request = new XMLHttpRequest(); 
  request.onreadystatechange=callback;
  request.open("Get","AjaxProcessor.aspx",true);
  request.send(null);



function callback()
{
    if(request.readyState==4)
        if(request.status==200)
            alert(request.responseText); //Get XML format data here
}
   


Example of DOM

Server -  AjaxProcessor.aspx :  
           
           XmlDocument doc = new XmlDocument();
            doc.****  // manipulate data in doc, include Insert, Remove or Replace

            //begin output to client
            Response.ContentType = "text/xml";
            Response.Clear();
            Response.Write(doc.InnerXml);
            Response.End();


Client - Ajax
 var request = new XMLHttpRequest(); 
  request.onreadystatechange=callback;
  request.open("Get","AjaxProcessor.aspx",true);
  request.send(null);

function callback()
{
    if(request.readyState==4)
        if(request.status==200)
       {    
               var info = request.responseXML.getElementsByTagName("age")[0].text;
                alert(info);
       }
}