Amortization Function

Anyone know of a GOOD amortization function that allows one to truly perform calcs based on all variables of a true loan amortization:
N (term)
PV (principal value)
INT (Interest rate)
PMT (payment amount)
FV (future value)
??
Nate
N (term)
PV (principal value)
INT (Interest rate)
PMT (payment amount)
FV (future value)
??
Nate