add_text_option("google_analytics_id", "Analytics ID: ");
        $sb->add_label("
(eg. UA-xxxxxxxx-x)");
        $event->panel->add_block($sb);
    }
    # Load Analytics tracking code on page request
    public function onPageRequest(PageRequestEvent $event)
    {
        global $config, $page;
        $google_analytics_id = $config->get_string('google_analytics_id', '');
        if (stristr($google_analytics_id, "UA-")) {
            $page->add_html_header("");
        }
    }
}