public function destroy($id)
 {
     $message = Message::findOrFail($id);
     if ($message->receiver_id != user()->id and $message->creator_id != user()->id) {
         $this->alertError(trans('app.access_denied'));
         return;
     }
     if ($message->creator_id == user()->id) {
         $message->creator_visible = false;
         $message->save();
     }
     if ($message->receiver_id == user()->id) {
         $message->receiver_visible = false;
         $message->save();
     }
     if ((!$message->creator_visible or $message->sent_by_system) and !$message->receiver_visible) {
         Message::destroy($id);
     }
     $this->alertFlash(trans('app.deleted', ['Message']));
     return Redirect::to('messages/inbox');
 }