ecshop如何调分类ID是3的分类名称

<li class="undis a_mid" id="sub4">
{foreach from=$categories item=cat}
{if $cat.id eq 3}
{foreach from=$cat.cat_id item=child}　
&middot;<a href="{$child.url}">{$child.name|escape:html}</a> 　
{/foreach}
{/if}
{/foreach}