I know what you mean about SBT source code and DBC issues. I'm working on a job-costing application for in house use that integrates with SBT Pro 5.0. It's a separate application, so it doesn't use any SBT source code, but I still have to understand SBT source code.

N-tier desing separates the interface (forms), business logic (customer's credit limit must be > $5,000), and data.

>Thanks for the response. We are an SBT VAR, and sell mostly Pro 5.0. We are called upon to do modifications that range from making simple tweeks in SBT programs (print two POs at a time, etc.), to fixing some of the SBT bugs, to producing more elaborate applications such as commission calculators. This last category of real applications is a growth area for us, hence the need for the framework. If you've ever looked at SBT code, you'll understand our desire to make our own applications as much as possible, integrating through data or global variables. SBT cannot use DBC at the present. What is n-tier?
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>Thanks again,
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>Steve