protected function clearSortingList()
    {
        PromoBlockListStore::instance()->sorting->clear(PromoBlockListStore::SORT_DEFAULT);
        PromoBlockListStore::instance()->sorting->clear(PromoBlockListStore::SORT_DATE_BEGIN_ASC);
        PromoBlockListStore::instance()->sorting->clear(PromoBlockListStore::SORT_DATE_BEGIN_DESC);
        PromoBlockListStore::instance()->sorting->clear(PromoBlockListStore::SORT_DATE_END_ASC);
        PromoBlockListStore::instance()->sorting->clear(PromoBlockListStore::SORT_DATE_END_DESC);
    }