public function post()
 {
     //admin-navigation
     $admin_navigation = new AdminNavigation();
     if ($admin_navigation->isNavigate()) {
         return $admin_navigation->goToN();
     }
     //handle upload file
     if (Input::hasFile('file_to_upload')) {
         $file_patth = storage_path();
         $file_upload_key = 'file_to_upload';
         $csvUtil = new CsvUtil($file_patth, $file_upload_key);
         $data = $csvUtil->parse();
         //now try import by csvUtil :)
         if (Input::has('model')) {
             $csvUtil->import(Input::get('model'));
             $this->messageController->send($csvUtil->getNotify(), $this::MESSAGE_KEY);
             return Redirect::to('admin/csv')->with('data', $data);
         }
     }
     if (Input::has('export-result')) {
         $contestants = Contestant::where('result', '>=', 0)->get();
         $data = array();
         foreach ($contestants as $contestant) {
             $data[] = array($contestant->id, $contestant->result, $contestant->email);
         }
         return CsvUtil::export($data);
     }
     //as a fallback
     return Redirect::to('admin/csv');
 }