Hazarding a guess ..

Perhaps you mean something like this in say,
D1: =IF(A1="Yes",B1*C1,0)

D1 will only compute B1*C1 if A1 contains a "Yes",
otherwise D1 will house a zero
--
Max
Singapore
http://savefile.com/projects/236895
xdemechanik
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"Dr_Ray" wrote in message
...
In Excel 2003, I want to automatically zero out a cell where data has
already
been entered by a user when a third cell is changed to a prespecified
value.