// number_format
function comma(num){
	return num.toString().replace(/([\d]+?)(?=(?:\d{3})+$)/g, function (t) { return t+","; });
}

function setResult(){
	var kinri = document.form.kinri.value;
	var kikan = document.form.kikan.value;
	var hensai = document.form.hensai.value;

	if(kinri.search(/^[0-9\.]+$/) == -1 || kikan.search(/^[0-9]+$/) == -1 || hensai.search(/^[0-9\.]+$/) == -1)
	{
		alert('半角数字で入力してください。');
	}
	else if(kikan > 35)
	{
		alert('期間は３５年までで入力してください。');
	}
	else if(kinri > 100)
	{
		alert('金利はは１００以内の数字でで入力してください。');
	}
	else
	{
		kinri = kinri / 100;
		riritsu = kinri / 12;
		kaisu = kikan * 12;
		a = 1 - Math.pow(1 + riritsu, -(kaisu));
		kanou = Math.floor(a * hensai / riritsu);
		kanou = comma(kanou);

		document.getElementById('result').innerHTML = kanou + ' 万円';
	}
}