dede织梦导航栏目实现三级栏目调用的方法

<div id="navMenu">
        <ul>
          <li {dede:field name=typeid runphp="yes"}(@me=="")? @me=" class='on'":@me="";{/dede:field}><a href="/">首页</a></li>
          {dede:channelartlist typeid='top' row='10' currentstyle="home"} //currentstyle 可以实现栏目切换时改变class状态，但需要修一些文件，具体看下面一段代码
          <li class='{dede:field.currentstyle/}'><a href="{dede:field name='typeurl'/}"  rel='dropmenu'>{dede:field name='typename' /}</a>
            <div id="erji" class="erji hide" style="position: absolute;width: 200px">
            {dede:sql sql='select * from dede_arctype where reid =~id~ '}
                <dl style="position: relative;height: 30px">
                <a href="[field:typedir function='str_replace("{cmspath}","",@me)'/]" target='_self'
                title="[field:typename/]" style="width: 90%;padding-left:10%;text-align:left;line-height: 30px">[field:typename/]</a>
                <div id="sanji" class="hide" style="position: absolute;width: 200px;left: 200px;background: #0D6598;">
                [field:id runphp='yes']
                        global $dsql;
                        $id=@me;
                        $sql='Select * from dede_arctype where reid='.$id.' ORDER BY id limit 0,20';
                        $dsql->SetQuery($sql);
                        $dsql->Execute();
                        while($row = $dsql->GetArray()){
                            $url = str_replace("{cmspath}","",$row['typedir']);
                            $str .='<a href="'.$url.'" style="display: block;width: 90%;padding-left: 10%;text-align: left;line-height: 30px;">'.$row['typename'].'</a>';
                            @me = $str;
                        }                      
                        if(@me == $id){ //避免3级栏目为空时 写出分类ID，这里加以判断 
                          @me ='';
                        }
                  [/field:id]
                </div>
              </dl>
              {/dede:sql}
            </div>
          </li>
          {/dede:channelartlist}
        </ul>
</div>