Calculate Yearly Sales Difference

Hello,
I've been using Crystal Reports a little bit for about a year now, but have never created a report like this.

The report I am working on displays:
CUSTOMER
2005 SALES $000000.00
2006 SALES $000000.00
TOTAL SALES $000000.00
$ DIFFERENCE $000000.00
% DIFFERENCE $000000.00

I am able to bring up the yearly sales and total sales, but I cannot figure out how to calculate the difference. Any help will be greatly appreciated.

Thank you.I think you must create a query in command query in database expert:
one command query for select sum(sales) from tablename where year=2005 group by year... also another command query for 2006 and compute the difference between the two field in report using formula.

i know it is not nice suggestion but if you have no other idea then try this.|||Thanks for the idea.
I'll take a look and see if I can get it to work.sql