I have to check two columns to determine if I pull the sums from a third. So
I need a sumif formula that accepts two criteria. For example:

I need to get the sum of values in column C where column A=Account 1 and
column B=Cost Center 2 (answer in this case would be 2,000):

A B C
Account 1 Cost Center 1 1,000
Account 1 Cost Center 2 2,000
Account 1 Cost Center 3 3,000
Account 2 Cost Center 1 500
Account 2 Cost Center 2 250
Account 2 Cost Center 3 425

Any ideas on how to get Excel to accept both criteria?