I have a long list of transactions based on departments that is always
changing.
A department can make more then one transaction so that department number
can appear more then once in a file. I want a function that will sum the
amount of an item used by each department.

ie.

Department Amount
50010 10.00
50010 15.00
50012 20.00
50010 6.00

ect..
Problem I am facing is I don't know which departments will be making
transactions for the week so i can't use the simple sumif with the criteria
being a certain department number.