I need a formula that will calculate the rate of return of an investment for
any period with multiple additions and withdrawals. For example:

7/31/06 $100,000 Beginning balance of investment
7/04/06 (5,000) Withdrawal
7/11/06 10,000 Deposit
7/16/06 (1,250) Withdrawal
7/27/06 $ 1,900 Deposit

8/31/06 $106,125 Ending value of investment (includes appreciation
of $475)

What is the rate of return for the month? or if this was for any period of
time (6-months, year etc)?

Thanks...Craig