Hi

I'm using the following sumproduct:
=SUMPRODUCT(--(Costs!$F$12:$F$57=$B7),--(MONTH(Costs!$H$12:$H$57)=1),Costs!$J$12:$J$57)

Costs!H12:H57 is a list of dates - on occassion this may be blank but there
still be a value in the Costs!J12:J57 column. For some reason, if the date
field is blank then the value is included in the calculation (as though there
was a January date in the date field).

I want it to ignore the value if the date field is blank - anyone got any
ideas? (I obviously have a column for each month (MONTH= 1 through 12))

Thanks