hi again - I hope it's OK to ask 2 questions on the same day! This problem
is related to the one I posed earlier, but more general.

Let's say a sheet has 3 columns. Columns A and B contain numbers, but there
are also varying numbers of blank cells. I'm looking for a formula I can
drag down in column C that sums the B value (if it exists) and the first A
value encountered on the same row or above. Here is a sample.

A B C
6 1 7
7 13

3 9
8
4 12

2 10
7 3 10

What drag-down formula can I use in Column C?
I'm really knew at this, and I'm grateful for any clues.
Victoria