public function bindAll($request)
 {
     // this is just hack for limitation of MemberConfigForm
     if (isset($request['member_config']['secret_answer'])) {
         $memberConfig = $request['member_config'];
         $memberConfig['secret_answer'] = md5($memberConfig['secret_answer']);
         $request['member_config'] = $memberConfig;
     }
     parent::bindAll($request);
 }