The original question is from :
> The title is like this: "A" is the sales manager and he has 2 downline,
> which is "B" and "C". "B" has 2 downline,which is "D" &"E"...
> So..the question is ..I want to know the total sales result of "A" downline,
> which is B,C,D and E...but can't used for loop because it will be very messy
> if there are lots of downline...
My curiosity is ... how to solve it in the very messy way:
* many direct downlines, not only 2.
* use loop, can't use recursive here !