<?php
function auth_send(){
    header('WWW-Authenticate: Basic realm="Closed Zone"');
    header('HTTP/1.0 401 Unauthorized');
    echo "<html><body bgcolor=white link=blue vlink=blue alink=red>"
    ,"<h1>Доступ запрещён</h1>"
    ,"<p>неправильные логин/пароль</p>"
    ,"</body></html>";
    exit;
};
        $login = "admin";
        $password = "12345";
        if (!isset($_SERVER['PHP_AUTH_USER'])) {
                auth_send();
        } else {
                $auth_user = $_SERVER['PHP_AUTH_USER'];
                $auth_pass = $_SERVER['PHP_AUTH_PW'];
                if (($auth_user != $login) || ($auth_pass != $password)) {
                        auth_send();}
        };
?>