function mortgage_calc()
{
	
	form = document.loanCalc;
	loan_amount = form.loan_amount.value;
    
	down_payment = "0";
	anuual_interest_rate = form.interest_rate.value / 100;
	years        = form.term.value;
	monthly_rate = anuual_interest_rate / 12;
	num_payments = years * 12;
	principal    = loan_amount - down_payment;
	
	month_payment= Math.floor(( principal*monthly_rate )/( 1-Math.pow(( 1+monthly_rate ),( -1*num_payments )))*100)/100;
	form.numer_of_payments.value = num_payments;
	form.monthly_payment.value   = month_payment;

    return true;

}