Uwierzytelnianie HTTP

<?php

If ($_SERVER['PHP_AUTH_USER'] != 'user' || $_SERVER['PHP_AUTH_PW'] != 'haslo')
	{
	header("WWW-Authenticate: Basic realm=Logowanie do systemu");
	header("HTTP/1.0 401 Unauthorized");
	echo 'błąd logowania';
	exit();
	}
// Wszystko poniżej jest chronione
echo 'zalogowany';

<?php

$tab['jan'] = 'haslo';
$tab['jurek'] = 'haslo2';
$tab['asia'] = 'haslo3';

If ($tab[$_SERVER['PHP_AUTH_USER']] != $_SERVER['PHP_AUTH_PW'] || !isset($_SERVER['PHP_AUTH_USER']))
	{
	header("WWW-Authenticate: Basic realm=Logowanie do systemu");
	header("HTTP/1.0 401 Unauthorized");
	echo 'błąd logowania';
	exit();
	}
echo 'zalogowany';

<?php

$tab[jan] = '207023ccb44feb4d7dadca005ce29a64';
$tab[jurek] = 'ed71c5d55af657bc2413020e5580d4dd';
$tab[asia] = 'daa9bda719032ae88abadb9cda4aa846';

If ($tab[$_SERVER['PHP_AUTH_USER']] != md5($_SERVER['PHP_AUTH_PW']) || !isset($_SERVER['PHP_AUTH_USER']))
	{
	header("WWW-Authenticate: Basic realm=Logowanie do systemu");
	header("HTTP/1.0 401 Unauthorized");
	echo 'błąd logowania';
	exit();
	}
echo 'zalogowany';