public function update(){
        $post = $_POST;
        $post['forum_cookie'] = md5('forum_'.intval($post['forum_sid']).'_'.intval($post['forum_pid']).intval($post['forum_uid']).'_'.intval($post['forum_cid']));
        //报错取消验证
        if($post['forum_sid'] == 24){
            D("Forum") -> setProperty("_validate", '');
        }
        //写入数据库
        $info = D("Forum")->ff_update($post);
        if($info){
            $email_type = '';
            if( $info['forum_sid'] == 5 ){
                if( C('user_email_guestbook') ){
                    $email_type = '留言';
                }
            }elseif( $info['forum_sid'] == 24 ){
                if( C('user_email_error') ){
                    $email_type = '报错';
                }
            }else{
                if( C('user_email_forum') ){
                    $email_type = '评论';
                }
            }
            if( $email_type ){
                D("Email")->send(C('site_email'), '站长您好', '收到用户（'.$info['forum_uid'].'）的'.$email_type, $info['forum_content']);
            }
            //返回状态
            if (C('user_check')) {
                $this->ajaxReturn($info, "谢谢，我们会尽快审核你的发言！", 201);
            }else{
                $this->ajaxReturn($info, "感谢你的参与！", 200);
            }
        }else{
            $this->ajaxReturn('', D("Forum")->getError(), 0);
        }
  }

function get_client_ip(){
   if (getenv("HTTP_CLIENT_IP") && strcasecmp(getenv("HTTP_CLIENT_IP"), "unknown"))
       $ip = getenv("HTTP_CLIENT_IP");
   else if (getenv("HTTP_X_FORWARDED_FOR") && strcasecmp(getenv("HTTP_X_FORWARDED_FOR"), "unknown"))
       $ip = getenv("HTTP_X_FORWARDED_FOR");
   else if (getenv("REMOTE_ADDR") && strcasecmp(getenv("REMOTE_ADDR"), "unknown"))
       $ip = getenv("REMOTE_ADDR");
   else if (isset($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], "unknown"))
       $ip = $_SERVER['REMOTE_ADDR'];
   else
       $ip = "unknown";
   return($ip);
}