public function hookHeader($params)
    {
        if (!$this->active || !Configuration::get('GOINTERPAY_STORE') || !Configuration::get('GOINTERPAY_SECRET')) {
            return false;
        }
        $html = '';
        if (version_compare(_PS_VERSION_, '1.5', '>')) {
            $this->context->controller->addJQueryPlugin('fancybox');
        } else {
            $html .= '
			<script type="text/javascript" src="' . __PS_BASE_URI__ . 'js/jquery/jquery.fancybox-1.3.4.js"></script>
		  	<link type="text/css" rel="stylesheet" href="' . __PS_BASE_URI__ . 'css/jquery.fancybox-1.3.4.css" />';
        }
        if (Tools::getValue('controller') == 'category') {
            $disable_add_to_cart = $this->_checkProuctForExportOnCategoryPage();
            $this->context->smarty->assign('disable_add_to_cart', $disable_add_to_cart);
        }
        $this->updateCurrencies();
        $details = Db::getInstance()->ExecuteS('SELECT i.`orderId`, o.`id_cart`, o.`id_order`' . (_PS_VERSION_ >= 1.5 ? ', o.`reference`' : '') . ' FROM `' . _DB_PREFIX_ . 'orders` as o, `' . _DB_PREFIX_ . 'gointerpay_order_id` as i WHERE o.`id_cart` = i.`id_cart` AND o.`id_customer` = ' . (int) $this->context->customer->id);
        $link = array();
        include_once _PS_MODULE_DIR_ . 'gointerpay/Rest.php';
        $rest = new Rest(Configuration::get('GOINTERPAY_STORE'), Configuration::get('GOINTERPAY_SECRET'));
        if (count($details)) {
            if (version_compare(_PS_VERSION_, 1.5, '<')) {
                foreach ($details as $detail) {
                    $link[(int) $detail['id_order']] = trim(Tools::safeOutput($rest->getOrderStatusLink($detail['orderId'])));
                }
            } else {
                foreach ($details as $detail) {
                    $link[Tools::safeOutput($detail['reference'])] = trim(Tools::safeOutput($rest->getOrderStatusLink($detail['orderId'])));
                }
            }
        }
        $this->context->smarty->assign(array('pathSsl' => (_PS_VERSION_ >= 1.4 ? Tools::getShopDomainSsl(true, true) : '') . __PS_BASE_URI__ . 'modules/gointerpay/', 'modulePath' => $this->_path, 'links' => $link, 'version15' => _PS_VERSION_ >= 1.5 ? true : false));
        $button = true;
        if (!$this->_isInternational($params['cart'])) {
            $button = false;
        }
        if ($button) {
            $alert = array();
            foreach ($params['cart']->getProducts() as $val) {
                if (!$this->_isExportProduct((int) $val['id_product'])) {
                    $alert[] = $this->l(Tools::safeOutput($val['name']) . ' is not a product that can be exported.');
                }
            }
            if (count($alert)) {
                $this->context->smarty->assign('alert', implode('\\n', $alert));
            }
        }
        if (Tools::getValue('step') < 1) {
            $button = false;
        }
        /* Check that the selected ship to country is available with Interpay */
        if (isset($this->context->cart->id_address_delivery) && $this->context->cart->id_address_delivery && Tools::getValue('ajax') == '') {
            $ship_to_address = new Address((int) $this->context->cart->id_address_delivery);
            if (Validate::isLoadedObject($ship_to_address)) {
                $ship_to_iso_code = Country::getIsoById((int) $ship_to_address->id_country);
                $ship_to_supported_by_interpay = Db::getInstance()->getValue('SELECT country_code FROM ' . _DB_PREFIX_ . 'gointerpay_countries WHERE country_code = \'' . pSQL($ship_to_iso_code) . '\'');
                if ($ship_to_supported_by_interpay != $ship_to_iso_code) {
                    $this->context->smarty->assign('interpay_not_supported', true);
                    $button = false;
                }
            }
        }
        $this->context->smarty->assign('button', $button);
        return $this->display(__FILE__, 'tpl/header.tpl');
    }