Rolling year

Hi all,

i want a report with rolling year. But i have no idea how to make it. Any help

I have a report with prompt for a range of CalYear/Month.

Example: CalYear/Month (start) = 10.2008 : CalYear/Month(end) = 9.2011

I want to create a table with this data:

1.row: SalesRevenue(CalYear/Month=10.2008 : CalYear/Month=9.2009)

2.row: SalesRevenue(CalYear/Month=10.2009 : CalYear/Month=9.2010)

3.row: SalesRevenue(CalYear/Month=10.2010 : CalYear/Month=9.2011)

The values in table should vary on the user response in prompt.

Any ideas for a simple or complicated formula ?

Thank you,

regards Martin Zluky