Problems:
a) .dbf files? Access can peer into a couple of them but not the majority.
b) They are not willing to spend money on software so things need to be freeware
c) This tracking will be implemented over a number of stores and if you ever want to see a shining example of non-computer-literate people...
Any ideas? I imagine a little GUI with radio buttons and a database query behind it, but WTHDIK (but what the hell do I know)
