thinkphp中怎么获取FCK编辑器中的内容

提交文章内容时，返回提交内容失败，我也是刚用FCK编辑器，请大家帮帮忙，看哪错了。
action代码
   class ArticleAction extends Action{
           public function add()
             {
   vendor("FCKeditor.fckeditor");
   $editor=new FCKeditor();
   $editor->Width='800';
   $editor->Height='500';
   $this->Value="";//设置编辑器的初始值
   $editor->InstanceName='comment';
   $html=$editor->Createhtml();//创建在线编辑器html代码字符串,并赋值给字符串变量$html.
   $this->assign('html',$html);
         $this->display();
    }
          public function save()
  {
                 $info=D("Article");
                 $result=$info->create();
              if(!empty($result))
                   {
                $this->success("添加文章成功！");
                   }
               else{
                 $this->error("添加文章失败！");
                   }
    }
    }
 
html代码
<html>
    <head>
          <title>添加文章</title>
    </head>
    <body>
         <form id="comment" name="comment" action="__URL__/save" method="post">
              <table>
                  <tr>
                       <td>
                            添加新评论：<input type="text" name="title">
                       </td>
                  </tr>
                  <tr>
                        <td>
                            {$html}
                        </td>
                  </tr>
                  <tr>
                  <input type="hidden" name="comment" id="comment">
                        <td>
                            <input type="submit" value="提交评论">
                        </td>
                  </tr>              </table>
            </form>
    </body>
</html>