<?php 
 class EmptyAction extends Action{ 
 function _empty(){ 
  header("HTTP/1.0 404 Not Found");//使HTTP返回404状态码 
  $this->display("Public:404"); 
 } 
 } 
 ?>

<configuration>
 <system.web>
 <customErrors mode=”On” defaultRedirect=”error.asp”>
 <error statusCode=”404″ redirect=”notfound.asp” />
 </customErrors>
 </system.web>
 </configuration>

<%
 Response.Status = “404 Not Found”
 %>
 

 if(//如果没有任何结果)
   {
   //以前是仅仅显示“该帖子已经不存在”的提示，现在是：
   require('/404.php');
   @header('HTTP/1.1 404 Not Found'');
   @header('Status: 404 Not Found');
   exit;
   }