Untitled

<?php

$login = "admin";
$password = "admin";

if (isset($_POST['submit'])) {
    if ($_POST['login'] == $login && $_POST['password'] == $password) {
        header('Location: http://test:81/auth.php'); exit;
}
    else {
        echo "Неверный логин или пароль";
}
}
?>
<!DOCTYPE html>
<html>
<head>
    <title></title>
</head>
<body>
<form  action="action.php" method="POST">
    <p>Логин<input type="text" name="login"/></p>
    <p>Пароль<input type="text" name="password"/></p>
    <input type="submit" name="submit" value="Оправить" />
</form>
</body>
</html>