public HttpResponseMessage Get(string id)
 {
     try
     {
         int           user_id = Convert.ToInt32(((ClaimsIdentity)(User.Identity)).FindFirst("id").Value);
         preg_question data    = dao.GetItemByID(Convert.ToInt32(id)).Where(c => c.custom_question_by_user_id == null || c.custom_question_by_user_id == user_id).FirstOrDefault();
         if (data != null)
         {
             return(Request.CreateResponse(HttpStatusCode.OK, data));
         }
         else
         {
             HttpError err = new HttpError(SysConst.DATA_NOT_FOUND);
             return(Request.CreateErrorResponse(HttpStatusCode.NotFound, err));
         }
     }
     catch (Exception ex)
     {
         HttpError err = new HttpError(ex.Message);
         return(Request.CreateErrorResponse(HttpStatusCode.NotFound, err));
     }
 }