oracle object selections

I am new to OO within oracle and am having trouble doing what i'm sure, many of you will view as a trivial piece of programming.

I have a 'Customer' table, which contains a 'Loyalty_card' object within one of its columns.

Code:

---

select name, id from customer_objtab
where Loyalty_card = Loyalty_card_objtyp('loyaltyid', 'id123',0);

---

The above code, returns the name and id as expected.

What I would like to do however, is return a row from my customer table, when its loyalty card object has a specific id. How would I do this?
In pseudo code, what I want is:

"select * from customer_objtab
where the loyalty card it contains
has an ID value of 'loyaltyid'".

Cheers.
(DB OO n00b).


EDIT:

I have solved the problem as follows but being a new post, am unable to delete it:

select name, id from customer_objtab
where TREAT(Loyalty_card AS Loyalty_card_objtyp).ID = 'loyaltyid';

Thanks anyway.

You could also use:

select name, id from customer_objtab o
where o.loyalty_card.id = 'loyaltyid';