JS格式化金额的函数（千分位，补两位小数）
代码：人懒，不用做多解释了吧。
function niceamount(amount) {
amount = amount.toString().replace(/\$|\,/g, '');
if (isNaN(amount))
amount = "0";
sign = (amount == (amount = Math.abs(amount)));
amount = Math.floor(amount * 100 + 0.50000000001);
cents = amount % 100;
amount = Math.floor(amount / 100).toString();
if (cents < 10)
cents = "0" + cents;
for (var i = 0; i < Math.floor((amount.length - (1 + i)) / 3); i++)
amount = amount.substring(0, amount.length - (4 * i + 3)) + ',' +
amount.substring(amount.length - (4 * i + 3));
return (((sign) ? '' : '-') + amount + '.' + cents);
}