Here's an example of how you could do that.

Original formula may be:
=A1+B1

But if A1 is PTO, then:
=IF(A1="PTO",0,A1)+B1

HTH,
Paul

"John Krsulic" <John wrote in message
...
I am trying to create what I would call an if/then formula in Excel 2003.
If
someone types the letters PTO into a cell have tat equal zero in the
formula.
I have a sum formula of a set of cells I want Excel to be able to add a
zero
into the formula if someone types the letters PTO into the cell. My
formula
works great until someone types letters into a cell then - of course -I
get a
value error in the cell.