Formula on Report

[This Guy]

I have a report that is briefly set up like this:

WE MD
2/06/05 169
2/13/05 145
2/20/05 189
2/27/05 104
Feb TTL 607

3/06/05 133
3/13/05 50
3/20/05 107
3/27/05 351
Mar TTL 641

WeekEnd, MonthEnd, and MD are my controls. What I need is a formula on each
month end that adds this months total MD with last months total MD. For
instance in my example I would need a column to the right of Mar TTL 641
that adds 641+607. Is this possible in Access and if so how? Thanks for any
help.

 

[This Guy]

Thank you so much. I knew there was a way to do it, I just couldn't think of
it.