Cascaded comboboxes in a form

[luca]

I'm trying to create a simple database, to keep track of different objects which I grouped in categories and subcategories. So I have 3 tables:
-category (cat. ID, cat. name)
-subcategory (subcat ID, cat. ID as FK, subcat. name)
-(i.e.)invoice (inv.ID, subcat ID, other fields)
I've created an invoice form (see attachment) with two synchronized combo boxes where I can select the cat./subcat. to store in the invoice.


It works fine as an entry form... but if I want to view, or even worse, to edit existing data, it doesn't.
How can I make the form to allow me to edit the records in a decent manner?
Should I have two forms - one for data entry and one for editing? VERY confused about this!
Thank you for any input!

[luca]

I apologies for posting these stupid questions! I'm sure they've been answered a thousand times before, one way or another... I'm just annoying good people. You know, we get born alone (except for twins), we live and create our databases alone and we die alone...
I'll keep reading and hope I'll find my way home.
Thanks to all of you!

[Rainlover]

Did you really solve your problem or did you just gave in.