=SUMPRODUCT((A1:A20=PO)*(B1:B20=PN),C1:C20)

Jerry

Sumif wrote:

I have three coloumn A=PO; B=Part # and C=quantity. And I would like to sum
the quantity for a part # of a particular PO. How should I make a sumif
function? Also could "IF" function nested into a sumif function.

Thank you.

Regards
Carmen