如何删除php SESSION数组中的行？

Question

Putting together a shopping cart with "add to cart" feature. Everything works except for removing an item from the cart. Here is the simplified version of what I have, to make it easier to see where the problem is:

$action = $_GET['action'];
$id     = $_GET['id'];
if ($action == "remove"){
    unset($_SESSION['cart'][$product_id][$id]);
    //Also tried this without sucess: $_SESSION['cart'][$product_id]--;
}

foreach($_SESSION['cart'] as $product_id) {
    echo 'Details'.$product_id['title'].' - '.$product_id['price'];
    echo '<a href="Cart.php?action=remove&id='.$product_id['product_id'].'">Remove</a>';
}

Answer 1

should just be able to call:

unset($_SESSION['cart'][$id]);