javascript - How to change dynamic select to ul navigation form. Ask for guidance.

<code>     <!-- 大系列 -->
            <td style="visibility: hidden;">{$lang.big_series}<select name="big_cate_id" id="big_cate_id">
                    <option value="">{$lang.please_select}</option>
                    {foreach from=$big_series item=big}<option value="{$big.sapval}" rel="{$big.cat_id}">{$big.cat_name}</option>{/foreach}
                </select>
            </td>
        </tr>                    
            <!-- 小系列 -->
           <!-- <td>{$lang.sub_series}<select name="sub_cate_id" id="sub_cate_id" onchange="searchGoods();">
                    <option value="">{$lang.please_select}</option>
                    {foreach from=$sub_series item=sub}<option value="{$sub.sapval}" class="s{$sub.parent_id}">{$sub.cat_name}</option>{/foreach}
                </select>
            </td>                                     -->
            <!-- 商品号or商品名 -->
        <tr>
            <td align="center">
                <input type="text" name="keyword" size="15" placeholder="产品名(号)" style="height:19px;line-height:19px;" />
                <input type="submit" value="搜索产品" class="button" />
            </td>
        </tr>
        <tr>
            <td>{$lang.sub_series}<select name="sub_cate_id" id="sub_cate_id" onchange="searchGoods();" size="20">
                  
                    {foreach from=$sub_series item=sub}<li value="{$sub.sapval}" class="s{$sub.parent_id}">{$sub.cat_name}</li>{/foreach}
                    
                </select>
            </td> 
        </tr>
 
 
 $(document).ready(function(){
    $('#big_cate_id').change(function(){
        var sapval = $(this).val();
        var cat_id = 0;
        $(this).find('option').each(function(){
            if($(this).attr('value') == sapval){
                cat_id = $(this).attr('rel');
            }
        });
        $('#sub_cate_id').empty();
        $('#sub_cate_id').append('<option value="">{$lang.please_select}</option>');
        if(sapval == ''){
            for(var i=0,len=subcate.length; i<len; i++){
                $('#sub_cate_id').append("<option value='"+ subcate[i].sapval +"'>" + subcate[i].cat_name + "</option>");
            }
        }else{
            for(var i=0,len=subcate.length; i<len; i++){
                if(subcate[i].parent_id == cat_id){
                    $('#sub_cate_id').append("<option value='"+ subcate[i].sapval +"'>" + subcate[i].cat_name + "</option>");
                }
            }
        }
    });
});
{/literal}
listTable.recordCount = {$record_count};
listTable.query = 'list';
listTable.pageCount = 1;
{foreach from = $filter item = item key = key}
listTable.filter.{$key} = '{$item}';
{/foreach}
  function searchGoods() {
    listTable.filter['big_cate_id'] = document.forms['searchForm'].elements['big_cate_id'].value;
    listTable.filter['sub_cate_id'] = document.forms['searchForm'].elements['sub_cate_id'].value;
    listTable.filter['keyword'] = Utils.trim(document.forms['searchForm'].elements['keyword'].value);
    listTable.filter['src'] = '{$src}';
    listTable.loadList();
}

![图片描述][1]
</code>

<code>     <!-- 大系列 -->
            <td style="visibility: hidden;">{$lang.big_series}<select name="big_cate_id" id="big_cate_id">
                    <option value="">{$lang.please_select}</option>
                    {foreach from=$big_series item=big}<option value="{$big.sapval}" rel="{$big.cat_id}">{$big.cat_name}</option>{/foreach}
                </select>
            </td>
        </tr>                    
            <!-- 小系列 -->
           <!-- <td>{$lang.sub_series}<select name="sub_cate_id" id="sub_cate_id" onchange="searchGoods();">
                    <option value="">{$lang.please_select}</option>
                    {foreach from=$sub_series item=sub}<option value="{$sub.sapval}" class="s{$sub.parent_id}">{$sub.cat_name}</option>{/foreach}
                </select>
            </td>                                     -->
            <!-- 商品号or商品名 -->
        <tr>
            <td align="center">
                <input type="text" name="keyword" size="15" placeholder="产品名(号)" style="height:19px;line-height:19px;" />
                <input type="submit" value="搜索产品" class="button" />
            </td>
        </tr>
        <tr>
            <td>{$lang.sub_series}<select name="sub_cate_id" id="sub_cate_id" onchange="searchGoods();" size="20">
                  
                    {foreach from=$sub_series item=sub}<li value="{$sub.sapval}" class="s{$sub.parent_id}">{$sub.cat_name}</li>{/foreach}
                    
                </select>
            </td> 
        </tr>
 
 
 $(document).ready(function(){
    $('#big_cate_id').change(function(){
        var sapval = $(this).val();
        var cat_id = 0;
        $(this).find('option').each(function(){
            if($(this).attr('value') == sapval){
                cat_id = $(this).attr('rel');
            }
        });
        $('#sub_cate_id').empty();
        $('#sub_cate_id').append('<option value="">{$lang.please_select}</option>');
        if(sapval == ''){
            for(var i=0,len=subcate.length; i<len; i++){
                $('#sub_cate_id').append("<option value='"+ subcate[i].sapval +"'>" + subcate[i].cat_name + "</option>");
            }
        }else{
            for(var i=0,len=subcate.length; i<len; i++){
                if(subcate[i].parent_id == cat_id){
                    $('#sub_cate_id').append("<option value='"+ subcate[i].sapval +"'>" + subcate[i].cat_name + "</option>");
                }
            }
        }
    });
});
{/literal}
listTable.recordCount = {$record_count};
listTable.query = 'list';
listTable.pageCount = 1;
{foreach from = $filter item = item key = key}
listTable.filter.{$key} = '{$item}';
{/foreach}
  function searchGoods() {
    listTable.filter['big_cate_id'] = document.forms['searchForm'].elements['big_cate_id'].value;
    listTable.filter['sub_cate_id'] = document.forms['searchForm'].elements['sub_cate_id'].value;
    listTable.filter['keyword'] = Utils.trim(document.forms['searchForm'].elements['keyword'].value);
    listTable.filter['src'] = '{$src}';
    listTable.loadList();
}

![图片描述][1]
</code>