function getAmortization()
	{
	var a = document.getElementById('loan_amount').value;
	var n = document.getElementById('loan_period').value;
	var p = document.getElementById('interest_rate').value;
	var i=0;
	/* Calculate amortization and write table to text area **/
	var payment = getPayment(a,n*12,p);
	document.getElementById('loan_repayments').value = Math.round(payment*100)/100;
	return false;
	}
function getPayment(a,n,p)
	{
	/* Calculates the monthly payment from annual percentage
	   rate, term of loan in months and loan amount. **/
	var acc=0;
	var base = 1 + p/1200;
	for (i=1;i<=n;i++) 
		{
		acc += Math.pow(base,-i);
		}
	return a/acc;
	}