protected function checkBrandIDField()
    {
        //Check "brand_id" field
        if ($this->obElement->getOriginal('brand_id') == $this->obElement->brand_id) {
            return;
        }

        //Update product ID cache list for brand
        ProductListStore::instance()->brand->clear($this->obElement->brand_id);
        ProductListStore::instance()->brand->clear((int) $this->obElement->getOriginal('brand_id'));
    }