织梦怎么实现下拉搜索指定栏目功能？

<form action="{dede:field name='phpurl'/}/search.php" name="formsearch">    <div class="form">    <input type="hidden" name="kwtype" value="0" />    <input name="keyword" type="text" class="search-keyword" id="search-keyword" />    <select name="typeid" class="search-option" id="typeid">       <option value='0' selected='1' class="search-xl">全部栏目</option>      {dede:channelartlist typeid='top' }   {dede:type} <option value='[field:id/]'>[field:typename/]</option>{/dede:type}      {dede:channel type='son' noself='yes'}   <option value='[field:id/]'>-[field:typename/]</option>   {/dede:channel}{/dede:channelartlist}</select>    <button type="submit" class="search-submit">站内搜索</button>    </div>    </form>  

<form action="{dede:global.cfg_cmsurl/}/plus/search.php" method="get" id="globalsearchform">      <div class="globalsearchform">          <input name="q" type="text" class="input" id="globalsearchform_key" name="key" value="输入关键词搜索产品..."  ="if(this.value=='输入关键词搜索产品...'){this.value='';}"   ="if(this.value==''){this.value='输入关键词搜索产品...';}">      </div>      <div class="globalsearchformselect">          <select name="typeid" class="search-option" id="typeid">          {dede:channelartlist typeid='9,10'}{dede:type}           <option value='[field:id/]'>[field:typename/]</option>{/dede:type}               {dede:channel type='son' noself='yes'}<option value='[field:id/]'>-[field:typename/]</option>{/dede:channel}           {/dede:channelartlist}           </select>      </div>      <div class="globalsearchform1">          <input type="image" class="imgbutton" src="{dede:global.cfg_templets_skin/}/images/searchr.png" id="button" name="imageField">      </div>  </form>