In my spreadsheet I calculate the percentage of an over charged amount.
Sometimes its negative or positive. The formula for the over(positive)
amount is =j2/f2. I copy this down the column. This works, but when a
negative amount is calculated, I need to manually change the formula to the
negative column.

What I want to know is there a way to create a statement that will check to
see if there is a positive or negative amount in the formula, and if not,
just to place a zero there.