I can't figure out the formula to get this calculator to work
http://www.smartmoney.com/retirement...tory=moneylast

I've tried combining the payment and PV functions and I can get it to work
if return is 0% with some inflation rate, but I can't figure out hot to
factor the two together.

If a portfolio is equal to 25,000 and it has to last 2 years (24 periods)
given a rate of return of 5% and an inflation rate of 4% the maximum yearly
withdrawal is
$12,805.

What is the formula in Excel to generate this number?