public function addBaseParams()
    {
        $order = $this->getOrder();
        $config = $this->getPayPalConfig();
        $basket = $this->getBasket();
        $session = $this->getSession();
        $lang = $this->getLang();
        $request = $this->getRequest();

        $request->setParameter("TOKEN", $session->getVariable("oepaypal-token"));
        $request->setParameter("PAYERID", $session->getVariable("oepaypal-payerId"));

        $request->setParameter("PAYMENTREQUEST_0_PAYMENTACTION", $this->getTransactionMode());
        $request->setParameter("PAYMENTREQUEST_0_AMT", $this->formatFloat($basket->getPrice()->getBruttoPrice()));
        $request->setParameter("PAYMENTREQUEST_0_CURRENCYCODE", $basket->getBasketCurrency()->name);
        // IPN notify URL for PayPal
        if (!$config->suppressIPNCallbackUrl()) {
            $request->setParameter("PAYMENTREQUEST_0_NOTIFYURL", $config->getIPNCallbackUrl());
        }   

        // payment description
        $subj = sprintf($lang->translateString("OEPAYPAL_ORDER_CONF_SUBJECT"), $order->oxorder__oxordernr->value);
        $request->setParameter("PAYMENTREQUEST_0_DESC", $subj);
        $request->setParameter("PAYMENTREQUEST_0_CUSTOM", $subj);

        // Please do not change this place.
        // It is important to guarantee the future development of this OXID eShop extension and to keep it free of charge.
        // Thanks!
        $request->setParameter("BUTTONSOURCE", $config->getPartnerCode());
    }