Hi!

Try this:

=SUMPRODUCT(--(A1:A100="xyz"),--(B1:B100=""),C1:C100)

Biff

"Dorian C. Chalom" wrote in message
...
What if i want to sum on the third column based on the value in columns 2
and 3

i.e.
column1 must = "XYZ"
and coulmn2 must be blank