function String_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);
}

String.prototype.endsWith = function (str) {
    var lastIndex = this.lastIndexOf(str);
    return (lastIndex != -1) && (lastIndex + str.length == this.length);
}

String.prototype.trim = function () {
    return this.replace(/^\s+|\s+$/g, "");
}
String.prototype.ltrim = function () {
    return this.replace(/^\s+/, "");
}
String.prototype.rtrim = function () {
    return this.replace(/\s+$/, "");
}