Thanks for your reply, it's a good article.

Perhaps i don't understand how to use the n-tier objects. i thought the idea was that each time you made a call to the data you would, from the interface, instantiate the business rules object and from there it would call to the data layer. The data layer would then return the results and be closed by the business object (released) and the business object would in turn return the results to the interface which would then release the business rules. is this not the way it is done?
are the connections from the interface to the data layer supposed to remain open until the application is closed?

thanks
Jordan