Cancel Merchandise Plan Payment

Hi,

I want that when a user cancels the payment of a merchandise, auto action writes a record into a specific table in the database. what is the right trigger and what are the variables to set?

I set:
trigger: onCPayAfterPaymentStatusUpdateEvent

type: Code

User: Self

Conditions:
value: [var4] equal to RegistrationCancelled

Action: PHP
Code:
$db = JFactory::getDbo();
$query_update = "UPDATE `#__comprofiler` SET `cb_campo_libero` = 'deleted' WHERE `user_id` = '853' ";
$db->setQuery($query_update);
$db->execute();

the problem seems that the trigger doesn't fire...

Where I'm wrong?

Thanks

I found the solution
there was another auto action that blocked the execution
now everything works
thanks