Модераторы контента и неуникальность никнейма

private function add(){
 
        if (!$this->request->isAjax()) { cmsCore::error404(); }
 
        $name = $this->request->get('name');
 
        if (!$name) { cmsCore::error404(); }
 
        $template = cmsTemplate::getInstance();
 
        $users_model = cmsCore::getModel('users');
 
       /* тут бяда... */$user = $users_model->filterEqual('nickname', $name)->getUser();
 
        if ($user===false){
            return $template->renderJSON(array(
                'error' => true,
                'message' => sprintf(LANG_CP_USER_NOT_FOUND, $name)
            ));
        }
 
        $moderators = $this->content_model->getContentTypeModerators($this->ctype['name']);
 
        if (isset($moderators[$user['id']])){
            return $template->renderJSON(array(
                'error' => true,
                'message' => sprintf(LANG_MODERATOR_ALREADY, $name)
            ));
        }
 
        $moderator = $this->content_model->addContentTypeModerator($this->ctype['name'], $user['id']);
 
        if (!$moderator){
            return $template->renderJSON(array(
                'error' => true,
                'message' => LANG_ERROR
            ));
        }
 
        return $template->renderJSON(array(
            'error' => false,
            'name' => $name,
            'html' => $template->render('ctypes_moderator', array(
                'moderator' => $moderator,
                'ctype' => $this->ctype
            ), new cmsRequest(array(), cmsRequest::CTX_INTERNAL)),
            'id' => $user['id'],
        ));
 
    }