How to work out the month prior to the last full month

[Kelser]

I am using Crystal 11. I have a date field and I need to look up the last month, which works fine using the LastFullMonth function. However, I also want to be able to see information for the month previous to that, whatever that month is. So, if I use this function today:
{Book.DateIn} = LastFullMonth
it pulls up the information for November. Now, I also want to see the information for October - as in LastFullMonth - 1. Can anyone help me? I'm not technical so will need a clear explanation!
Many thanks in advance.

 

[BobSuruncle]

Try using the DateSerial function.
It allows you to use offsets to the month specified.
For example:

{Book.DateIn} in DateSerial (Year(CurrentDate),Month(CurrentDate)-2,1) to DateSerial (Year(CurrentDate),Month(CurrentDate),1-1)

This code goes back 2 months from the 1st day of the Current month and ends at the last day of the last full month.

Bob Suruncle