public function execute()
 {
     try {
         $where = null;
         $fields = array(credencialTableClass::ID, credencialTableClass::NOMBRE, credencialTableClass::DESCRIPCION);
         $orderBy = array(credencialTableClass::ID);
         $page = 0;
         if (request::getInstance()->hasGet('page')) {
             $page = request::getInstance()->getGet('page') - 1;
             $page = $page * config::getRowGrid();
         }
         $f = array(credencialTableClass::ID);
         if (request::getInstance()->hasGet('page')) {
             $this->page = request::getInstance()->getGet('page');
         } else {
             $this->page = $page;
         }
         $lines = config::getRowGrid();
         $this->cntPages = credencialTableClass::getAllCount($f, true, $lines, $where);
         $this->objCredencial = credencialTableClass::getAll($fields, true, $orderBy, 'ASC', config::getRowGrid(), $page, $where);
         $this->defineView('index', 'credencial', session::getInstance()->getFormatOutput());
     } catch (PDOException $exc) {
         echo $exc->getMessage();
         echo '<br>';
         echo '<pre>';
         print_r($exc->getTrace());
         echo '</pre>';
     }
 }