I have developed a Budget File and a Requisition File. I would like to link the two in such a way that (1) a message would pop up if someone is requesting supplies from a budget line item that does not have the funds to cover that purchase, or (2) better yet stop the user from continuing with the request, that is, prevent the new record of that request from being completed? This is to become one part of a larger purchase order program. Thanks.

Tight control over creation of new records is typically handled with a layout for data entry where all the fields are global fields. A user can enter all the data, but nothing is "posted" until a button is clicked / a script is run. In your scenario, the script would first check the budget, and if ok, a new record would be created and the data fields would be set to their corresponding global fields (and you'll probably want to empty all the globals afterwards).

The way the script checks the budget would simply be something like:

If (gAmount > BudgetLineItem::Amount)

. Show Message ("No way, Jos