php用户登录代码

     $admin_name="admin";
        $admin_pawd="admin";
        if($php_auth_user!=$admin_name||$php_auth_pw!=$admin_pawd)
        {
                header('www-authenticate: basic realm="系统验证"');
                header('http/1.0 401 unauthorized');
                echo "服务器拒绝请求,你没有权限!";
                exit();
        }

//

  if (empty($_server['php_auth_user'])) {
    header("content-type: text/html; charset=big5");
    header('www-authenticate: basic realm=" authentication "');
    header('http/1.0 401 unauthorized');
    echo '请输入正确的账号及密码, 不可以取消!';
    exit;
  } else {
    echo "你登录的账号是 ".$_server['php_auth_user']."
";
    echo "你使用的密码是 ".$_server['php_auth_pw']."

";
    $correctname="john";
    $correctpwd="1234" ;
     if (($_server['php_auth_user'] != $correctname) or
            ($_server['php_auth_pw'] !=$correctpwd)){
        echo "登录失败, 请打开新的浏览器重新登录";
     }else{
     echo "登录成功.....";
     }
  }
?>

   if (($_post['name'] != "john") or ($_post['passwd'] != "1234")):
?>
  
  
  
   未输入账号或密码, 或账号,密码不正确

";
     echo "你登录的账号是 ".$_post['name']."
";
     echo "你使用的密码是 ".$_post['passwd'];
   endif
?>