In an detail section of an order form for a store with
several hundred products, I need to use a control to
select the desired product category, of which there are
20, and have that selection filter the product records
shown in a combo box. I have written source to alter the
row source property of the products combo box, using an
unbound combo box in the detail section of the form.

The problem is, when you change the product category,
every line in the detail section of the form shows the
newly chosen category, when I only want it to apply to the
currently selected line.

Using a 'categories' combo box in the form header would
work, but would make a really awkward interface for users
because you would have to bounce back and forth from
header to your product line, resetting the category each
time.

Any ideas?