categories and sub categories

[Gate Bouchard]

sorry for my english

I have created a product database. Each product belong to
a category and a subcategory.

I am trying to create a method to select the subcategory
for the product in a form. The drop down menu content
must be related to the selected category.

Exemple :

available categories : house, car, boat
available subcategories : small house, big house, small
car, big car, small boat, big boat.

I have assigned a key to the the category and subcategory
tables so i can connect subcategories that belongs to a
specific category.

I can easily create ASP pages that would allow me to
dynamically select a subcategory from a drop down menu
that would contain only related options but I can't do it
directly in access from a drop down.

Any clues...