public function destroy_action()
 {
     if ($this->_validate()) {
         require_once UNOSLIDER_BASE . '/application/models/unoslider_presets.php';
         $model = new Unoslider_Presets_Model();
         $model->delete($_POST['id']);
         $response = json_encode(array('success' => true));
         header("Content-Type: application/json");
         echo $response;
     }
     exit;
 }