<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
     <title>Untitled Page</title>
     <script src="jquery-1[1].2.1.pack.js" type="text/javascript"></script>
     <script  type="text/javascript">
        $(document).ready(
        function()
        {
          $("#ajbt").click(
               function()
              {
                  $("#loadimg").ajaxStart(
                       function()
                        {
                         $("#loadimg").css("display","block");
                         }
                  );

               // $.ajaxTimeout( 500000000 );
                  $.ajax(
                  {
                    type: "get",
                    url: "WebForm3.aspx",
                    datatype:"text",
                    data: "name=John",
                  complete:function()                                                   
                   {
                    $("#loadimg").css("display","none");
                    },
                   success: function(msg){


                                          $("#a").html(msg);
                                          }
                 }
                  );
                }
          );
          $("#loadimg").css("display","none");
       }
    );

     </script>
</head>
<body>
<input type="button" value="ajaxdata" id="ajbt"/>
<div id="a"><img src="Utility/spinner.gif" id="loadimg" ></div>
</body>
</html>




default.aspx

protected void Page_Load(object sender, EventArgs e)
        {
           //System.Threading.Thread.Sleep(2000);
            if (!this.IsPostBack)
                if (Request["name"].ToString() != "")
                {
                    httpresponse(Request["name"].ToString());
                }
                else
                {
                    httpresponse(Request["name"].ToString());
                }
        }
        public void httpresponse(string name)
        {
            //HttpContext.Current.Response;
            HttpContext.Current.Response.Write(name);
        }