Help! Sum of a range based on two variables

Hey! I'm trying to create a simple checkbook application for a friend. I've gotten pretty much everything I want figured out except for two functions, which are basically the same thing. I'm trying to find the sum of all deposits and of all withdrawals based on two entered dates. Basically, they enter the dates, and the formula finds the dates, then sums all the deposits/withdrawals between them. Can anyone help? I attached the workbook with some sample data in case I wasn't really clear. Thanks!

In M12:
=SUMPRODUCT(--($D$6:$D$300>=$M$8),--($D$6:$D$300<=$M$9),$G$6:$G$300)

In M13:
=SUMPRODUCT(--($D$6:$D$300>=$M$8),--($D$6:$D$300<=$M$9),$F$6:$F$300)
(this one DOES match your sample total)