>I created a Sales Commission Report using VFP's Report Designer.
>[question about summing snipped]

Heres's a trick I've used a couple of times.

Set a report variable's value to be an iterative sum. If nSum is your value,
set it's definition as:

nSum = nSum + [stuff you are accumulating]

Initial value is zero

Reset at appropriate break

In the function column, select 'Nothing'.

I think the accumulation only takes place whenever you use the variable. (Unfortunately, it might be recalculated for every detail line that prints, I'm not sure). But play around with it. It might work.