导航上获取了几个一级栏目，但是点二级栏目时候无法高亮一级栏目，只有顶级栏目会亮

<yang:catlist typeid="316" type='son' flag='1' limit="20">

<li class="m-list">

<a <if condition = "$cid eq $catlist['id']">class="active"</if> href="{$catlist.url}">{$catlist.name}</a>

<span class="menu_btn"></span>

<ul class="m_2">

<volist name='catlist["child"]' id='v'>

<li ><a href="{:U('List/index',array('cid'=>$v['id']))}" <if condition = "$cid eq $v['id']">class="active open"</if>>{$v.name}</a></li>

</volist>

</ul>

</li>

</yang:catlist>