I have a daily fuel log table with an incrementing number, vehicle serial number, odometer reading and the amount of fuel pumped. How can I write a function to tell Webfocus to use the reading of the odometer from the previous fill in my equation?

You will have to sort the data to be in the order you want and then you can use the LAST function.

Here is a doc found on the tech support site that shows you how to use LAST.

http://documentation.informationbuilders.com/masterinde...func/datasource4.htm

Thank you I was just looking at that function