MoneyFormat Class in ActionScript 2.0

I've been asked for an AS2 version of my original MoneyFormat Class, by quite some people, so I decided to do quick conversion, and post it here. I'll be working on this to extend its functionality very soon.

Enjoy.
+LA

/**
* MoneyFormat, Version 1.
* Transforms regular numbers into Currency Format.
* Makes use of the String Class
* Updates at: www.lordalex.org - reach@lordalex.org
*
* @author: LordAlex Leon
* @version: 1.0.0
**/
class MoneyFormat extends String {
private var _sign:String;
private var _sep:String;
private var _dec:String;
private var _decimals:Boolean;
/**
* MoneyFormat Constructor
* @param sign_param [String] The currency sign. ie: "$"
* @param sep_param [String] The unit delimiter. ie: ","
* @param dec_param [String] The decimal delimiter. ie: "."
* @param decimals_param [Boolean] Option to display last 2 decimal places. ie: true or false
**/
function MoneyFormat(sign_param:String, sep_param:String, dec_param:String, decimals_param:Boolean) {
(sign_param == undefined) ? _sign="$" : _sign=sign_param;
(sep_param == undefined) ? _sep="," : _sep=sep_param;
(dec_param == undefined) ? _dec="." : _dec=dec_param;
(decimals_param == undefined) ? _decimals=true : _decimals=decimals_param;
}
/**
* toMoney method
* Takes one paramter and transforms the value into money format
* @param amount_param [String] Takes in a String value.
**/
public function toMoney(amount_param:String):String {
if ((amount_param == "") || (amount_param == undefined)) {
return "";
} else {
var _myDot:Number;
var _myString:String;
var myvalue:String;
var cents:String;
var myLength:Number;
var divide:Number;
var dollars:String;
(amount_param) ? _myString=amount_param.toString() : _myString="";
_myDot = _myString.indexOf(".");
if (_myDot<=0) {
myvalue = _myString;
cents = "00";
} else {
myvalue = _myString.substr(0, _myDot);
cents = _myString.substr(_myDot+1, _myString.length);
}
if (myvalue.length>0) {
myLength = myvalue.length;
divide = myLength/3;
if ((myLength%3) == 0) {
divide = (myLength/3)-1;
}
for (var i = 1; i<=divide; i++) {
myvalue = myvalue.substr(0, (myLength-(3*i)-(i-1)))+_sep+myvalue.substr((myLength-(3*i)-(i-1)), (3*i)+(i-1));
myLength = myvalue.length;
}
dollars = myvalue;
}
if (cents.length>2) {
cents = cents.substr(0, 2)+_dec+cents.substr(2, cents.length);
} else if (cents.length == 1) {
cents = cents+"0";
}
if (_decimals) {
return _sign+dollars+_dec+cents;
} else {
return _sign+dollars;
}
}
}
}