SUMPRODUCT Question Adding Hours?

[wx4usa]

I have columns as follows:
A = Month Text
B = Year
C= Employee
D=time in
E= time out
F= Hours worked (Out minus in) Formatted as hours/minutes Time
format 5:45

I need a formula that works...mine doesnt.
=sumproduct((a10:a1000=August)*(b10:b1000=2009)*(c10:c1000=Mike)*
(hours))

This formula returns a zero.

Thanks for your help!

 

[muddan madhu]

=SUMPRODUCT(--(A2:A5="April")*(B2:B5=2009)*(C2:C5="a")*(F2:F5))