Using last months data in this months formula 1

[fryguy5049]

I have a database that has about 10 variables for each month of the year. i.e. each row is a month. I am trying to display the figures from each variable, but I also need to add some formulas that calculate a difference between this months variable1 and last months variable1. I want the report to show the data for the whole year, but how do I reference previous months variables in a formula ?
Here is a sample of the data:
date var1

1/31/23004 $25
2/29/2004 $32

thanks!

 

[Katy44]

There is a Previous({fieldName}) function - does that help?

 

[fryguy5049]

cool, that worked. thanks!