By using quotes you're telling Excel to return a string or text, not a sum.
Use this instead

=IF(E18<0,sum(c24-e17)-c17,sum(c24-c17))


"Shellack" wrote:

I don't think there are any problems in this "if" statement, but it's not
returning any values; it just shows the entire formula in the cell.

=IF(E18<0,"=sum(c24-e17)-c17","=sum(c24-c17)")

When I test the statements separately, they come back with a value just
fine. I even tried deleting the =sum in the formula thinking there should
only be one = sign at the beginning of the formula, but that didn't work. It
doesn't give me the #VALUE message either indicating something is wrong in
this formula. Any ideas??

Oh yeah....I'm using Office 2000.