private function key($content)
 {
     import('ORG.Util.KeyReplace');
     $key = M('key');
     $keys = $key->field('url,title,num')->select();
     $map = array();
     foreach ($keys as $k => $v) {
         $map[$k]['Key'] = $v['title'];
         $map[$k]['Href'] = "<a href=\"{$v['url']}\" target=\"_blank\">{$v['title']}</a>";
         $map[$k]['ReplaceNumber'] = $v['num'];
     }
     $a = new KeyReplace($map, $content);
     $a->KeyOrderBy();
     $a->Replaces();
     return $a->HtmlString;
 }