protected JsonResult UpdateUserOwnedEntity(UserOwnedEntity entity)
 {
     if (ModelState.IsValid)
     {
         try
         {
             var userId = CurrentUserId;
             entity.UserId = userId;
             _db.Entry(entity).State = entity.EntityKey == 0 ? EntityState.Added : EntityState.Modified;
             _db.SaveChanges();
         }
         catch (SimpleException ex)
         {
             ModelState.AddModelError("", ex.Message);
         }
         catch (Exception)
         {
             ModelState.AddModelError("", Strings.UpdateFailed);
         }
     }
     var errMsgs = GetModelStateErrorMsgs();
     var jsonResult = new
     {
         errMsg = errMsgs.Any() ? errMsgs[0] : null,
     };
     return Json(jsonResult);
 }
 protected JsonResult DeleteUserOwned(UserOwnedEntity entity)
 {
     if (entity != null && entity.UserId == CurrentUserId)
     {
         _db.Entry(entity).State = EntityState.Deleted;
         _db.SaveChanges();
     }
     else
     {
         return Json("Failed to delete");
     }
     return Json("Deleted");
 }