public HttpResponseMessage Delete(string id)
 {
     try
     {
         int           user_id = Convert.ToInt32(((ClaimsIdentity)(User.Identity)).FindFirst("id").Value);
         preg_question item    = dao.GetItemsByParams(new preg_question()
         {
             id = Convert.ToInt32(id)
         }).Where(c => c.custom_question_by_user_id == null || c.custom_question_by_user_id == user_id).FirstOrDefault();
         dao.DeleteData(item);
         return(Request.CreateResponse(HttpStatusCode.Accepted, SysConst.DATA_DELETE_SUCCESS));
     }
     catch (Exception ex)
     {
         HttpError err = new HttpError(ex.Message);
         return(Request.CreateErrorResponse(HttpStatusCode.BadRequest, err));
     }
 }