public function getValidationMessages()
    {
        $messages = null;
        if (isset($this['validation-messages'])) {
            $message = null;
            foreach ($this['validation-messages'] as $val) {
                $message .= "<li>{$val}</li>\n";
            }
            $messages = "<ul class='validation-message'>\n{$message}</ul>\n";
        }
        return $messages;
    }