Sumif for 2 criteria in different columns

=SUMPRODUCT(--(A4:A11>=D1),--(A4:A11<=D2),--(B4:B11=D3),C4:C11)

Assumptions:

D1 contains start date
D2 contains end date (both dates are inclusive)
D3 contains type of interest

Richard

=SUMPRODUCT(--($A$4:$A$11>=DATE(2009,1,4)),--($A$4:$A$11<=DATE(2009,1,10)),--($B$4:$B$11="one"),$C$4:$C$11)

the date references etc can of course be references to cells containing the criterion.

for more info. on Sumproduct see: http://www.xldynamic.com/source/xld.SUMPRODUCT.html