Computing a value on a form using a multiplier from a second table.

[jkoca]

I have two tables...

tblPlants
....Category
....Cost
....Selling Price

tblCategory
....Description
....MarkupPercent

On the form for the Plant Table, for each change in the Cost, I would like
to reach across to the category, fetch the markup, and compute the selling
price.

My questions are:

Which event can I use to determine that a change has occurred in the Cost
(eg. Old Value Not Equal New Value)

How do I fetch the markup value from the other table

I would appreciate whatever help anyone could provide...

Thanks,

Jim Koca