<style type="text/css">
.search_bar{background:url(/e/images/diy/search_bar.gif) no-repeat left center;padding:5px 0 0 40px;height:28px;width:198px;border:1px solid #d6dbe1;}
.search_bar .s_keyword{width:120px;height:18px;border:1px solid #cccccc}
.search_bar .s_bt{background:url(/e/images/diy/search_btn.gif) no-repeat 0 0;width:59px;height:20px;border-width:0px}
</style>
<div class="search_bar">
<input type="text" id="s_keyword" class="s_keyword" maxlength="20" value="请输入关键词">
<input type="button" value="" class="s_bt">
</div>
这是搜索代码，怎么无效呢
