//php实现上一篇、下一篇

获取当前浏览文章id
$id = isset($_GET['id']) > 0 ? intval($_GET['id']) : "";

下一篇文章
$query = mysql_query("SELECT id,title FROM article WHERE id>'$id' ORDER BY id ASC LIMIT 1"); 
$next = mysql_fetch_array($query);

上一篇文章
$query = mysql_query("SELECT id,title FROM article WHERE id <'$id' ORDER BY id DESC LIMIT 1"); 
$prev = mysql_fetch_array($query);

页面显示上一篇和下一篇文章标题和链接：
<div class="page_nav clearfix"> 
    <div title="下一篇" class="next_page"> 
        <a href="?id=<?php echo $next['id']; ?>"><?php echo $next['title']; ?></a>         
    </div> 
    <div title="上一篇" class="pre_page"> 
        <a href="?id=<?php echo $prev['id']; ?>"><?php echo $prev['title']; ?></a>  
    </div> 
 </div>

基于thinkPHP框架：
<?php
$up = M('Content')->where(array('id' => array('gt',$id),'del'=>1,'cid'=>$cont['cid']))
         ->order('id asc')->find();
$this -> assign('up',$up);//上一篇
 
$dw = M('Content')->where(array('id' => array('lt',$id),'del'=>1,'cid'=>$cont['cid']))
     ->order('id desc')->find();
$this -> assign('dw',$dw);//下一篇
?>