Avoid error with simple subtraction function

[wjsubs]

I have a subtraction function that gives me a net profit value. I wa
hoping that someone knows how to keep a row without data in it fro
displaying an error value in the profit column.

I am trying to do a running average that will change as new dates ar
entered into the database.

Having error values produces an error value for my average value.

here is my setup-> gross-expenses=profit

The average is a simple average function that has been auto-filled 10
data points ahead for easy data entry in the future.

Thanks guys,
Wil

 

[Tom Ogilvy]

in the cell producing the error

=if(iserror(formula),"",formula)