织梦dede导航循环指定栏目出现 rel=＂nofollow＂的方法

{dede:channel type='top' row='8'}
<a href="[field:typelink/]" [field:id runphp=yes]
     if(@me == 1){
   @me = 'rel="nofollow"';
   }else if(@me == 9){
    @me = 'rel="nofollow"';
   }else if(@me == 5){
    @me = 'rel="nofollow"';
   }else if(@me == 8){
    @me = 'rel="nofollow" ';
   }else if(@me == 7){
    @me = 'rel="nofollow"';
   }else{@me = '';}
   [/field:id]  >[field:typename/]</a>
{/dede:channel}

function is_nofollow($id){
    switch ($id) {
      case '1':
         $nofollow = 'rel="nofollow"';
        break;
      case '2':
         $nofollow = 'rel="nofollow"';
        break;
      case '3':
         $nofollow = 'rel="nofollow"';
        break;
      case '4':
         $nofollow = 'rel="nofollow"';
        break;
      default:
         $nofollow = '';
        break;
    }
    return $nofollow;
}