function language_translate($slug = '')
{
    $code = get_language_code();
    $lang_file_dir = "./languages/{$code}.php";
    if (!is_file($lang_file_dir)) {
        $lang_file_dir = "./languages/en.php";
    }
    require $lang_file_dir;
    if (!isset($lang[$slug])) {
        require "./languages/en.php";
        if (!isset($lang[$slug])) {
            return $slug;
        }
        return $lang[$slug];
    } else {
        return $lang[$slug];
    }
}
			
             <?php 
    // --- bof -- ipdfbill --------
    $form = xtc_draw_form('pdf_bill', FILENAME_ORDERS, xtc_get_all_get_params(array('pdf')) . 'pdf=1');
    $input_deliverydate = xtc_draw_input_field('pdfbill_deliverydate', $_POST['pdfbill_deliverydate'], 'size="12"');
    $profile_list = profile_list();
    $values = array();
    foreach ($profile_list as $p) {
        if (strpos($p['profile_name'], '_invoice') !== false || $p['profile_name'] == 'default') {
            $values_invoice[] = array('id' => $p['profile_name'], 'text' => $p['profile_name']);
        }
        if (strpos($p['profile_name'], '_delivnote') !== false) {
            $values_delivery[] = array('id' => $p['profile_name'], 'text' => $p['profile_name']);
        }
    }
    $lc = get_language_code($_SESSION['language']);
    $input_profile_invoice = xtc_draw_pull_down_menu('profile_name_invoice', $values_invoice, 'profile_' . $lc . '_invoice');
    $input_profile_delivey = xtc_draw_pull_down_menu('profile_name_delivery', $values_delivery, 'profile_' . $lc . '_delivnote');
    $input_automatic_invoice = xtc_draw_checkbox_field('profile_automatic_invoice');
    $button_invoice_create = xtc_button(BUTTON_PDFBILL_CREATE, 'submit', 'name="pdf_invoice_generate" class="btn btn-default"');
    $button_invoice_recreate = xtc_button(BUTTON_PDFBILL_RECREATE, 'submit', 'name="pdf_invoice_generate" class="btn btn-default"');
    $button_invoice_sendmail = xtc_button(BUTTON_PDFBILL_SEND_INVOICE_MAIL, 'submit', 'name="pdf_invoice_sendmail" class="btn btn-default"');
    $button_invoice_sendmail2 = xtc_button(BUTTON_PDFBILL_SEND_INVOICE_MAIL2, 'submit', 'name="pdf_invoice_sendmail2" class="btn btn-default"');
    $button_delivery_create = xtc_button(BUTTON_PDFDELIVNOTE_CREATE, 'submit', 'name="pdf_delivery_generate" class="btn btn-default"');
    $button_faktur = '<a class="btn btn-default" href="' . xtc_href_link(FILENAME_ORDERS, xtc_get_all_get_params(array('pdf')) . 'pdf=1&action2=set_ibillnr') . '">' . BUTTON_BILL . '</a>';
    $filename = FILENAME_PDFBILL_DISPLAY . '?oID=' . $oID;
    //$button_invoice_display   = '<a class="btn btn-default" target="_new" href="' . xtc_href_link($filename) . '">' . BUTTON_PDFBILL_DISPLAY . '</a>';
    $button_invoice_display = '<a class="btn btn-default" target="_new" href="' . xtc_href_link($filename, "oID=" . $oID . "&file=" . get_pdf_invoice_filename($oID)) . '">' . BUTTON_PDFBILL_DISPLAY . '</a>';
    $filename = FILENAME_PDFBILL_DISPLAY;
    $button_delivery_display = '<a class="btn btn-default" target="_new" href="' . xtc_href_link($filename, "oID=" . $oID . "&file=" . get_pdf_delnote_filename($oID)) . '">' . BUTTON_PDFBILL_DISPLAY . '</a>';
    xtc_button(BUTTON_PDFBILL_DISPLAY, 'submit', 'name="pdf_invoice_display" class="btn btn-default"');