I am trying to put together a budget which will keep a running total. For
example, if I have, say $100/month allocated for food, I want every time I
type in the month's total, for it to add the difference and keep a running
total. Say this month I spend $84, next month $105. I want the cell to
calculate "+11.00." I can do that, but I need to account for the months in
the future which are now blank.

The way I'm doing it (=SUM((100-C13)+(100-C14)+etc.) will assume for the
months that are blank (i.e. the future) I have spent $0.00 on food.

What function do I need? Thanks.
--
CMS