protected function _preSave()
    {
        if ($this->isChanged('message'))
        {
            $maxLength = 420;
            if (utf8_strlen($this->get('message')) > $maxLength)
            {
                $this->error(new XenForo_Phrase('please_enter_message_with_no_more_than_x_characters', array('count' => $maxLength)), 'message');