more on cascade question

hey guys: ok, I got two tables, a and b. There is a field in a, let's call it ID, which is a primary key. There is a field in b, which has a foreign key points to a's ID. CD is set to yes for that foreign key. What I want to do is when I delete a entry in a, all relating records in b will be deleted automatically. However, when I attemp to delete a record in a now, my return is : SQL: -692: Key value for constraint (root.u213_215) is still being referenced. How do I get around that? thanks yan