Hello,

I have 2 sheets, one for 2008 and other for 2009. On each sheet I have
monthly data ($) and a cell with the sum of all the months. On the 2009 sheet
I will add a new figure monthly and this will add up the year total cell.
next to this one there is a year to date 2008 for comparison. So what I need
is that everytime that I type a number in a month on 2009, the year to date
2008 adds the same months... here the sample for better understanding...

2008
Revenue (USD)JUN JUL AUG SEPT OCT NOV DEC YTD 08 YTD 07
money 5 8 2 7 5 1 2 30 25

2009
Revenue (USD)JUN JUL AUG SEPT OCT NOV DEC YTD 09 YTD 08
money 5 6 4 15 15*

YTD= year to date
(*)Is there a formula that on YTD 08 adds the same months that already
contain data on 2009 extracting that data from 2008?? and doest it everytime
I add a number on a month in 2009?
thanks
please help!