>Thanks for the reply J.C.
>
>I saw the VFP documentation that says that it ignores NULL values. If it does, then why is it that x is not NULL? As you can see from my example code, I initalize x to NULL first then call the CALCULATE command.

Well, because calculate returns 0.00 and assigns it to the var. You can test this on the command window with 'set talk ON' CALCULATE outputs the result to the VFP screen.