<?php
session_start();
$username = $_POST['username'];
$password = $_POST['password'];

$_SESSION['username'] = $username;
$_SESSION['password'] = $password;

if ($username=="belajar" AND $password=="php"){
header('location: user');
}else{
if (ini_get("session.use_cookies")) {
    $params = session_get_cookie_params();
    setcookie(session_name(), '', time() - 42000,
        $params["path"], $params["domain"],
        $params["secure"], $params["httponly"]
    );
}
session_destroy();
echo "<script>alert('Username atau password salah!'); document.location.href=\"index.php\"</script>";
}
?>