1. if (!isset($_SERVER['PHP_AUTH_USER'])) { 
2.             header('WWW-Authenticate: Basic realm="LOGIN IN"'); 
3.             header('HTTP/1.0 401 Unauthorized'); 
4.             echo '请输入密码后访问'; 
5.             exit; 
6.         } elseif ($_SERVER['PHP_AUTH_USER']=='user' && $_SERVER['PHP_AUTH_PW']=='pass') { 
7.             echo "OK"; 
8.         } else { 
9.             header('HTTP/1.0 403 Forbidden'); 
10.         }