protected function _expireAjax() {
        if (!$this->getOnepage()->getQuote()->hasItems() || $this->getOnepage()->getQuote()->getHasError() || $this->getOnepage()->getQuote()->getIsMultiShipping()) {
            $this->_ajaxRedirectResponse();
            return true;
        }
        if (Mage::getSingleton('checkout/session')->getCartWasUpdated(true)) {
            $this->_ajaxRedirectResponse();
            return true;
        }
        return false;
    }