if(!empty($_POST['username'] && $_POST['pass'])) {
    $id=0;
    $username = $_POST['username'];
    $pass = $_POST['pass'];
    $result = mysqli_query($conn,"SELECT * FROM users WHERE username='" . $username . "' AND password = '". $pass ."'");
    if(mysqli_num_rows($result)==1) {

        while ($row = mysqli_fetch_assoc($result)) {
            $id = $row['id'];
            $type = $row['type'];
        }
        $_SESSION['username'] = $username;
        $_SESSION['id'] = $id;
        if ($type == 'admin') {

            header("Location: index_af_adm.php");

        } else {

            header("Location: index_af.php");
        }
    }else{

        $message='Username sau parola sunt invalide';
        header('Location: index.php?msg=1');

    }
}