Portal Calculation Question

[jrwhiteii]

Hello all,

I'm wondering if anyone knows of a technique or plug-in that will solve my problem.

I need FileMaker to perform "spreadsheet" like calculations in the following way using relations and portals:

DatabaseA - Customer List

DatabaseB - Each record represents End of Month total sales.

I'd like to be able to look at the customer in DatabaseA and see calculations that would represent the % increase/decrease in sales from record to record (which in this case would be month to month) and just for this customer (easily filtered through a portal).

I thought this would be easy at first, but I'm now finding that it's going to be a bit more difficult than I had first thought. Hopefully, though, not impossible.

Thank you,

Jim