只写一个表单，可以达到两个表单的效果

 1 <form action="__URL__/lists" method="POST">
 2             <input type="hidden" name="flag" value="search">
 3             标题:<input type="text" name="title" value="" class="queryInput">
 4             文章分类:<select name="cate" class="querySelect">
 5                 <option value="">请选择...</option>
 6                 <volist name="alist" id="vo">
 7                     <option value="{$vo.id}">
 8                         <?php
 9                             for($i=0;$i<$vo['count']*3;$i++){
10                                 echo "&nbsp;";
11                             }
12                         ?>
13                     {$vo.cname}{$vo.id}</option>
14                 </volist>
15             </select>
16             <input type="submit" value="查询" class="formbtn">
17 </form>

 1 if($_POST['title']!=""){
 2             $Article = D("Article");
 3             $title = trim($_POST['title']);
 4             $lists = $Article->where("title='$title'")->select();
 5             $this->assign('lists',$lists);
 6             $this->display();
 7         }elseif($_POST['cate']!=""){
 8             $Article = D("Article");
 9             $cid = $_POST['cate'];
10             echo $cid;
11             $lists = $Article->where("cid=$cid")->select();
12             $this->assign('lists',$lists);
13             $this->display();
14         }else{
15 。。。
16 }

用表单中的title和cate两个name分别是否为空来判断是提交的哪个单一表单。