Running total in calculation field in a report

[sgmarty]

Hi, I have an interesting problem.
Without using reduncant data, how can I design a calculation field to get a running total from values in different records? I'm designing a usage/month report, and I'm confused.
Date Value Calculation
Record1: 08/05/06 12345
Record2: 09/05/06 23456 (23456-12345)
Record3: 10/05/06 34567 (34567-23456)

Thanks for the help.
Steve

[PEB]

Hi Steve you can use

UNION QUERY

So do the query without calculation

Do a query with only one row the calculation but with the same columns

Than in SQL View Copy the Second One and paste it

in deleting the ; of the first and typing UNION

:)