protected void Page_Load(object sender, EventArgs e)
        {
            MessageFilter filter = null;

            try
            {
                string itemGuid = Request.QueryString["ItemGuid"];
                GetMessageControl();
                filter      = new MessageFilter();
                filter.Guid = new Guid(itemGuid);
                var resultObj = a_control.GetMessageTrackByGuid(filter);
                a_result = JsonConvert.SerializeObject(resultObj);
            }
            catch (Exception)
            {
            }
        }