织梦产品页折叠菜单，进入定位默认展开

织梦做产品栏目的时候，会有一级栏目和二级栏目，一般都喜欢用折叠的效果！！但是点击进入的话，默认会关闭！怎么才能让它默认打开呢！

 <script>
   $(document).ready(function () {
		openoff('#part2_{dede:field.id/}');
		openoff('#part2_{dede:field.reid/}');
	})
   function openoff(obj){
	   $(obj).next("dd").css("display","block");
	   $(obj).addClass("launched");
   }
   </script>

<div class="menu" id="sidebar" data-csnow="2" data-class3="0" data-jsok="2"> {dede:channelartlist typeid=27}
  <dl class="list-none navnow">
    <dt id='part2_{dede:field name="id"/}' ><a href='{dede:field name="typeurl"/}'  title='{dede:field name="typename"/}' ><span>{dede:field name="typename"/}</span></a></dt>
    <dd class="sub" style="display:none;"> {dede:channel type='son' noself='yes'}
      <h4 id='part3_[field:id/]'><a href="[field:typedir function="str_replace('{cmspath}','',@me)"/]"  title='[field:typename /]' class='nav'><span>[field:typename /]</span></a></h4>
      {/dede:channel}  </dd>
  </dl>
  {/dede:channelartlist}
  <div class="clear"></div>
</div>
  <Style type="text/css">
	.launched{background-image:url(/skin/images/nav_hover.jpg);color: #d5b687;}
 	.list-none{ list-style:none; padding:0px; margin:0px;}
	.menu dl{ margin-top:5px; }
	.menu dt{cursor: pointer;margin-top: 10px;font-weight: bold;font-size: 16px;font-family: "微软雅黑";color: #0d2180;line-height: 53px;padding-left: 48px;
background: url(/skin/images/nav.jpg) no-repeat;}
	.menu h4 a{ display: block; 200px;height: 28px;font-family: "微软雅黑";text-align: center;font-size: 14px;line-height: 28px;color: #333; }
	.menu h4 span{ display: block; 200px;height: 28px; font-weight:100;font-family: "微软雅黑";text-align: center;font-size: 14px;line-height: 28px;color: #333; }
	.menu h4 a:hover{color: #fff;background-color: #d5b687;}
</Style>