Groups total in report footer?

I have report like this:
in detail section
date1      - group 1
     data for AM -group 2
     data for PM
   total for group 2
  total for group 1

date2 ...
...
...
...

now I want in report footer to have total for AM data and PM data like this:

Total AM ......
Total PM ......

How to do that?

regard j

Create two running total fields AMTotal and PMTotal. Set them to summarize however you want (count records for example). Set the evaulation to use formula with the formula for AMTotal something like "Hour(date) < 12" and the PMTotal like "Hour(date) >= 12". Or however you have AM/PM defined in your group2. Finally just drop the two running total fields in the report footer to see the answers.