// $Id: mortgage_payment.js,v 1.1 2005/03/04 23:53:32 mzimniak Exp $ 
// 
// $Log: mortgage_payment.js,v $ 
// Revision 1.1 2005/03/04 23:53:32 mzimniak 
// initial upload 
// 
// 
function compute_payment(balance, rate, num_payments, pay_per_year) { 
	var payment; 
	if (rate <= 0.0) { 
		payment = balance * 1.0/(num_payments); 
	} 
	else { 
		payment = balance * (rate/100.0/pay_per_year) / (1.0 - Math.pow(1.0 + rate/100.0/pay_per_year, -num_payments)); 
	} 
	return Math.floor(payment * 100.0 + 0.5)/100.0; 
}