function doit(){
	var rate=0.01*document.getElementById('c1rate').value;
	var freqsel=document.getElementById('c1freq').selectedIndex;
	var freq=freqsel ? document.getElementById('c1freq')[freqsel].value : 1;
	var balance=document.getElementById('c1balance').value;
	var years=document.getElementById('c1years').value;
	var monthly=document.getElementById('c1payments').value;;
	var newmonthly=balance*rate/12/(1-Math.pow(1+rate/freq,-years*freq));
	document.getElementById('c1repayments').value=
		isFinite(newmonthly)?newmonthly.toFixed(2):'----';
	document.getElementById('c1increase').value=
		isFinite(newmonthly-monthly)?(newmonthly-monthly).toFixed(2):'----';
	setTimeout("doit();", 1);
}
doit();