ASP/ADO/VB.NET: How to update multiple datatables with typed datasets ?

[Bauhaus]

I made a database (http://users.skynet.be/fc042048/Pizza.jpg) in Access
which I want to use via typed datasets on my website. Problem is, if I i.e.
want to edit the datatable "Pizza" in a gridview, I get the error "Can't
delete or update the record because there are related records in the
datatable "PizzaOnderdelen" (means Pizza Ingredients).
What do I have to do to update the table ? Do I need to adjust my dataset
file (contains only the table 'Pizza") or do I have to change my VB code (I
made a Pizza object and update/delete/insert methods for the Pizza table) ?

(Here's the source code: Solution
(http://users.skynet.be/fc042048/Pizza (solution).rar) and Aspx files
(http://users.skynet.be/fc042048/Pizza (aspx files).rar))

Bauhaus.