if (file_exists($helper->path('language/assets/' . $lang . '/js/jquery.ui.datepicker-language.js'))) {
    $GLOBALS['xoTheme']->addScript($helper->url('language/' . $lang . '/js/jquery.ui.datepicker-language.js'));
    $GLOBALS['xoTheme']->addScript($helper->url('language/' . $lang . '/js/jquery.countdown.js'));
} else {
    $GLOBALS['xoTheme']->addScript($helper->url('language/english/js/jquery.ui.datepicker-language.js'));