判断顶级栏目是否有下级

{eyou:channel type="top" row="60" id="field" currentstyle="background:#0976dc"}

        {eyou:notempty name="$field.children"}

        <li class="menu"><a href="javacript:void(0);" style="{$field.currentstyle}">{$field.typename}</a>

          <ul class="sub">

            {eyou:channel name="$field.children" row="100" id="field1"}

 <li><a href="{$field1.typeurl}">{$field1.typename}</a> </li>

            {/eyou:channel}

          </ul>

          <span></span> </li>

        {eyou:else /}

        <li><a href="{$field.typeurl}" style="{$field.currentstyle}">{$field.typename}</a></li>

        {/eyou:notempty}  

 {/eyou:channel}