public HttpResponseMessage ManageNotificationGroups(NotificationGroupsModel obj)
 {
     using (NotificationTier mt = new NotificationTier())
     {
         try
         {
             return this.Request.CreateResponse(HttpStatusCode.OK, mt.ManageNotificationGroups(obj));
         }
         catch (Exception ex)
         {
             return this.Request.CreateResponse(HttpStatusCode.BadRequest, ex.Message);
         }
     }
 }
 public HttpResponseMessage RetrieveNotificationGroups()
 {
     IList<NotificationGroupsModel> response;
     using (NotificationTier mt = new NotificationTier())
     {
         response = mt.RetrieveNotificationGroups();
         return this.Request.CreateResponse(HttpStatusCode.OK, response);
     }
 }