Previous Month & Last 12 Month Based on UserResponse

Dear All Guru,

I have a report in which i need to show previous month and last 12 month data based on a UserResponse from a month selection.

Report Scenario Example:

User was ask to select [Successful Date] from the prompt which using 'BETWEEN' (From and To). Based on the selection, e.g

1 Nov 2013 to 31 Nov 2013.

Based on the selection above, i should show the result for previous month and last 12 months. Example

1. Previous Month = October 2013 to Nov 2013 result  (1 October 2013 - 31 Nov 2013)

2. Last 12 month = Nov 2012 - Nov 2013 (1 Nov 2012 - 31 Nov 2013)

I am wondering:

1. How should i write the previous month and last 12 month variable based on UserResponse?

2. How do i filter it based on this variable

Regards,

Joe