formatCurrency

function formatCurrency(num) {
    num = num.toString().replace(/\$|\,/g, '');
    if (isNaN(num))
        num = "0";

    sign = (num == (num = Math.abs(num)));
    num = Math.floor(num * 100 + 0.50000000001);
    cents = num % 100;
    num = Math.floor(num / 100).toString();

    if (cents < 10)
        cents = "0" + cents;

    for (var i = 0; i < Math.floor((num.length - (1 + i)) / 3); i++)
        num = num.substring(0, num.length - (4 * i + 3)) + ',' +

    num.substring(num.length - (4 * i + 3));

    return (((sign) ? '' : '(') + '$' + num + '.' + cents + ((sign) ? '' : ')') );

    // return (((sign) ? '' : '-') + '$' + num + '.' + cents);
}