Value sign if cell is blank

[summer2010]

Hello

I keep getting a value sign if cell AA3, AC3, AE3, AG3 or AI3 are blank.

=SUMPRODUCT(--(AB3:AB3="I"),AA3)+SUMPRODUCT(--(AD3:AD3="I"),AC3)+SUMPRODUCT(--(AF3:AF3="I"),AE3)+SUMPRODUCT(--(AH3:AH3="I"),AG3)+SUMPRODUCT(--(AJ3:AJ3="I"),AI3)

The above works lovely when there is an amount in either cells AA3, AC3, AE3, AG3 or AI3 but when the cells are blank it appears not to be working.

Can anyone advise please? I'm working on a sheet I've inherited and am having to make changes / update and a lot of the info is way beyond my knowledge of excel, although I'm gradually learning on the way.

Many Thanks :-)

[ramananhrm]

Please add this along --(AA3:AI3<>"")

[martindwilson]

that formula doesnt make sense
=SUMPRODUCT(--(AB3:AB3="I"),AA3)
is the same as =if(AB3="I",aa3,0)
try this instead
=SUMPRODUCT(--(AB3:AJ3="I"),--(MOD(COLUMN(AB3:AJ3),2)=0),AA3:AI3)
in fact
=SUMPRODUCT(--(AB3:AJ3="I"),AA3:AI3) should work
and even just
=SUMIF(AB3:AJ3,"I",AA3:AI3) which is the best choice

[summer2010]

Thank you all for your help, I'll have a play around with all the suggested ways. There are so many ways to get the answer I'm looking for that half a time I totally forget to try some of the easier ways like you've suggested Martindwilson :-) for sumif