dedecms织梦的循环次数的方法并做条件判断

{dede:arclist typeid='3' row='8'}
  [field:global.autoindex/]
{/dede:arclist}

{dede:arclist typeid='3' row='8'}
   <li class="m[field:global.autoindex/]">
      <a href="[field:arcurl/]"><img src="[field:litpic/]" /></a>
   </li>
[field:global name=autoindex runphp='yes'] 
 (@me!=4)? @me="":@me="<li class='on'></li>";
[/field:global]
{/dede:arclist}