public function cron_overdue_warning($cronoverdue) {
        global $CFG;
        if (!$cronoverdue) {
            return '';
        }

        if (empty($CFG->cronclionly)) {
            $url = new moodle_url('/admin/cron.php');
            if (!empty($CFG->cronremotepassword)) {
                $url = new moodle_url('/admin/cron.php', array('password' => $CFG->cronremotepassword));
            }

            return $this->warning(get_string('cronwarning', 'admin', $url->out()) . '&nbsp;' .
                    $this->help_icon('cron', 'admin'));
        }

        // $CFG->cronclionly is not empty: cron can run only from CLI.
        return $this->warning(get_string('cronwarningcli', 'admin') . '&nbsp;' .
                $this->help_icon('cron', 'admin'));
    }