Need help creating a sum based on variable data.

I have rows of data on a worksheed which represents proposals of all my reps.
Each Month is represented by a separate worksheet. Each row contains the
name of the rep in one cell (column c) and the dollar amount of the proposal
in another cell (column h). There are over 300 proposals in each worksheet
with 5 different reps. I need to create a sum in a different cell for each
rep. I can do this manually by sorting and selecting each rep each month. I
am wondering if there is a formula that will seach one column and sum all
values that are associated with a given value. is there a formula that will
accomplish this?