Basic question about the ONS update function, testing it out

[tcarden]

am getting going using the Observer/Notifier System and have a question

to test and see if the update function was running i did this....

function hazMatProduct() {
    $_SESSION['cart']->attach($this, array('NOTIFIER_CART_ADD_CART_END', 'NOTIFIER_CART_REMOVE_END'));
}

function update(&$class, $eventID, $paramsArray = array()) {
    $_SESSION['cart']->total = 0;
    } 

but when adding or updating the cart, the subtotal is not 0.
if the update function is running shouldn't ...

$_SESSION['cart']->total = 0; 

make the the cart subtotal be 0?

i'm certain the autoloaders are working correctly...