$conf['login'] = "имя";   
$conf['password'] = "пароль";   

function auth() {   
     global $confsp;   
     Header('WWW-Authenticate: Basic realm="Admin"');   
     Header('HTTP/1.0 401 Unauthorized');   
     die("Обломайсо бот!!!");   
}   
if ($conf['login'] != "" && $conf['password'] != "") {   
     if (!isset($_SERVER['PHP_AUTH_USER']) || !isset($_SERVER['PHP_AUTH_PW'])) auth();   
     if (!(($_SERVER['PHP_AUTH_USER'] == $conf['login']) && ($_SERVER['PHP_AUTH_PW'] == $conf['password']))) auth();   
}