var Cards = new makeArray(8);
Cards[0] = new CardType("MasterCard", "51,52,53,54,55", "16");
var MasterCard = Cards[0];
Cards[1] = new CardType("VisaCard", "4", "13,16");
var VisaCard = Cards[1];
Cards[2] = new CardType("AmExCard", "34,37", "15");
var AmExCard = Cards[2];
Cards[3] = new CardType("DinersClubCard", "30,36,38", "14");
var DinersClubCard = Cards[3];
Cards[4] = new CardType("DiscoverCard", "6011", "16");
var DiscoverCard = Cards[4];
Cards[5] = new CardType("enRouteCard", "2014,2149", "15");
var enRouteCard = Cards[5];
Cards[6] = new CardType("JCBCard", "3088,3096,3112,3158,3337,3528", "16");
var JCBCard = Cards[6];
var LuhnCheckSum = Cards[7] = new CardType();

/*************************************************************************\;
CheckCardNumber(form);
function called when users click the "check" button;
\************************************************************************;*/
function CheckCardNumber(campos) {
    var array_Card = campos;
    var tmpyear;
    if (array_Card[1].value.length == 0) {
        Ext.Msg.alert('Error!', 'Please enter a Card Number.');
        array_Card[1].focus();
        array_Card[1].select();
        return false;
    }
    if (array_Card[3].value.length == 0) {
        Ext.Msg.alert('Error!', 'Please enter the Expiration Year.');
        array_Card[3].focus();
        return false;
    }
    if (array_Card[3].value > 1996)
        tmpyear = array_Card[3].value;
    else if (array_Card[3].value < 21)
        tmpyear = array_Card[3].value;
    else {
        Ext.Msg.alert('Error!', 'The Expiration Year is not valid.');
        return false;
    }
    tmpmonth = array_Card[2].options[array_Card[2].selectedIndex].value;
    if (!(new CardType()).isExpiryDate(tmpyear, tmpmonth)) {
        Ext.Msg.alert('Error!', 'This card has already expired.');
        return false;
    }
    card = array_Card[0].options[array_Card[0].selectedIndex].value;
    var retval = eval(card + ".checkCardNumber(\"" + array_Card[1].value + "\", " + tmpyear + ", " + tmpmonth + ")");
    
    cardname = "";
    if (retval) {
        if (array_Card[4].value.length == 0) {
            Ext.Msg.alert('Error!', 'Please enter a Security Code.');
            array_Card[4].focus();
            array_Card[4].select();
            return false;
        }
        else {
            if (array_Card[0].value == "AmExCard") {
                if (array_Card[4].value.length <= 3) {
                    Ext.Msg.alert('Error!', 'Please enter a correct Security Code.');
                    array_Card[4].focus();
                    array_Card[4].select();
                    return false;
                }
            }
            else {
                if (array_Card[4].value.length <= 2 || array_Card[4].value.length == 4) {
                    Ext.Msg.alert('Error!', 'Please enter a correct Security Code.');
                    array_Card[4].focus();
                    array_Card[4].select();
                    return false;
                }
            }
        }
        // comment this out if used on an order form;
    }
    else {
        // The cardnumber has the valid luhn checksum, but we want to know which;
        // cardtype it belongs to.;
        for (var n = 0; n < Cards.size; n++) {
            if (Cards[n].checkCardNumber(array_Card[1].value, tmpyear, tmpmonth)) {
                cardname = Cards[n].getCardType();
                break;
            }
        }
        if (cardname.length > 0) {
            Ext.Msg.alert('Error!', 'This looks like a ' + cardname + ' number, not a ' + card + ' number.');
            return false;
        }
        else {
            Ext.Msg.alert('Error!', 'This card number is not valid.');
            return false;
        }
    }
    return true;
}
/************************************************************************;*\
Object CardType([String cardtype, String rules, String len, int year;
                                        int month]);
cardtype    : type of card, eg: MasterCard, Visa, etc;
rules       : rules of the cardnumber, eg: "4", "6011", "34,37";
len         : valid length of cardnumber, eg: "16,19", "13,16";
year        : year of expiry date;
month       : month of expiry date;
eg:;
var VisaCard = new CardType("Visa", "4", "16");
var AmExCard = new CardType("AmEx", "34,37", "15");
\************************************************************************;*/
function CardType() {
    var n;
    var argv = CardType.arguments;
    var argc = CardType.arguments.length;

    this.objname = "object CardType";

    var tmpcardtype = (argc > 0) ? argv[0] : "CardObject";
    var tmprules = (argc > 1) ? argv[1] : "0,1,2,3,4,5,6,7,8,9";
    var tmplen = (argc > 2) ? argv[2] : "13,14,15,16,19";

    this.setCardNumber = setCardNumber;  // set CardNumber method.;
    this.setCardType = setCardType;  // setCardType method.;
    this.setLen = setLen;  // setLen method.;
    this.setRules = setRules;  // setRules method.;
    this.setExpiryDate = setExpiryDate;  // setExpiryDate method.;

    this.setCardType(tmpcardtype);
    this.setLen(tmplen);
    this.setRules(tmprules);
    if (argc > 4)
        this.setExpiryDate(argv[3], argv[4]);

    this.checkCardNumber = checkCardNumber;  // checkCardNumber method.;
    this.getExpiryDate = getExpiryDate;  // getExpiryDate method.;
    this.getCardType = getCardType;  // getCardType method.;
    this.isCardNumber = isCardNumber;  // isCardNumber method.;
    this.isExpiryDate = isExpiryDate;  // isExpiryDate method.;
    this.luhnCheck = luhnCheck; // luhnCheck method.;
    return this;
}

/************************************************************************;*\
boolean checkCardNumber([String cardnumber, int year, int month]);
return true if cardnumber pass the luhncheck and the expiry date is;
valid, else return false.;
\************************************************************************;*/
function checkCardNumber() {
    var argv = checkCardNumber.arguments;
    var argc = checkCardNumber.arguments.length;
    var cardnumber = (argc > 0) ? argv[0] : this.cardnumber;
    var year = (argc > 1) ? argv[1] : this.year;
    var month = (argc > 2) ? argv[2] : this.month;

    this.setCardNumber(cardnumber);
    this.setExpiryDate(year, month);

    if (!this.isCardNumber())
        return false;
    if (!this.isExpiryDate())
        return false;

    return true;
}
/************************************************************************;*\
String getCardType();
return the cardtype.;
\************************************************************************;*/
function getCardType() {
	return this.cardtype;
}
/************************************************************************;*\
String getExpiryDate();
return the expiry date.;
\************************************************************************;*/
function getExpiryDate() {
	return this.month + "/" + this.year;
}
/*************************************************************************;\
boolean isCardNumber([String cardnumber]);
return true if cardnumber pass the luhncheck and the rules, else return;
false.;
\************************************************************************;*/
function isCardNumber() {
    var argv = isCardNumber.arguments;
    var argc = isCardNumber.arguments.length;
    var cardnumber = (argc > 0) ? argv[0] : this.cardnumber;
    if (!this.luhnCheck())
        return false;

    for (var n = 0; n < this.len.size; n++)
        if (cardnumber.toString().length == this.len[n]) {
        for (var m = 0; m < this.rules.size; m++) {
            var headdigit = cardnumber.substring(0, this.rules[m].toString().length);
            if (headdigit == this.rules[m])
                return true;
        }
        return false;
    }
    return false;
}

/************************************************************************;*\
boolean isExpiryDate([int year, int month]);
return true if the date is a valid expiry date,;
else return false.;
\************************************************************************;*/
function isExpiryDate() {
    var argv = isExpiryDate.arguments;
    var argc = isExpiryDate.arguments.length;

    year = argc > 0 ? argv[0] : this.year;
    month = argc > 1 ? argv[1] : this.month;

    if (!isNum(year + ""))
        return false;
    if (!isNum(month + ""))
        return false;
    today = new Date();
    expiry = new Date(year, month);
    if (today.getTime() > expiry.getTime())
        return false;
    else
        return true;
}

/************************************************************************;*\
boolean isNum(String argvalue);
return true if argvalue contains only numeric characters,;
else return false.;
\************************************************************************;*/
function isNum(argvalue) {
    argvalue = argvalue.toString();

    if (argvalue.length == 0)
        return false;

    for (var n = 0; n < argvalue.length; n++)
        if (argvalue.substring(n, n + 1) < "0" || argvalue.substring(n, n + 1) > "9")
        return false;

    return true;
}

/************************************************************************;*\
boolean luhnCheck([String CardNumber]);
return true if CardNumber pass the luhn check else return false.;
Reference: http://www.ling.nwu.edu/~sburke/pub/luhn_lib.pl;
\************************************************************************;*/
function luhnCheck() {
    var argv = luhnCheck.arguments;
    var argc = luhnCheck.arguments.length;

    var CardNumber = argc > 0 ? argv[0] : this.cardnumber;

    if (!isNum(CardNumber)) {
        return false;
    }

    var no_digit = CardNumber.length;
    var oddoeven = no_digit & 1;
    var sum = 0;

    for (var count = 0; count < no_digit; count++) {
        var digit = parseInt(CardNumber.charAt(count));
        if (!((count & 1) ^ oddoeven)) {
            digit *= 2;
            if (digit > 9)
                digit -= 9;
        }
        sum += digit;
    }
    if (sum % 10 == 0)
        return true;
    else
        return false;
}

/************************************************************************;*\
ArrayObject makeArray(int size);
return the array object in the size specified.;
\************************************************************************;*/
function makeArray(size) {
    this.size = size;
    return this;
}

/************************************************************************;*\
CardType setCardNumber(cardnumber);
return the CardType object.;
\************************************************************************;*/
function setCardNumber(cardnumber) {
    this.cardnumber = cardnumber;
    return this;
}

/************************************************************************;*\
CardType setCardType(cardtype);
return the CardType object.;
\************************************************************************;*/
function setCardType(cardtype) {
    this.cardtype = cardtype;
    return this;
}

/************************************************************************;*\
CardType setExpiryDate(year, month);
return the CardType object.;
\************************************************************************;*/
function setExpiryDate(year, month) {
    this.year = year;
    this.month = month;
    return this;
}

/************************************************************************;*\
CardType setLen(len);
return the CardType object.;
\************************************************************************;*/
function setLen(len) {
    // Create the len array.;
    if (len.length == 0 || len == null)
        len = "13,14,15,16,19";

    var tmplen = len;
    n = 1;
    while (tmplen.indexOf(",") != -1) {
        tmplen = tmplen.substring(tmplen.indexOf(",") + 1, tmplen.length);
        n++;
    }
    this.len = new makeArray(n);
    n = 0;
    while (len.indexOf(",") != -1) {
        var tmpstr = len.substring(0, len.indexOf(","));
        this.len[n] = tmpstr;
        len = len.substring(len.indexOf(",") + 1, len.length);
        n++;
    }
    this.len[n] = len;
    return this;
}

/************************************************************************;*\
CardType setRules();
return the CardType object.;
\************************************************************************;*/
function setRules(rules) {
    // Create the rules array.;
    if (rules.length == 0 || rules == null)
        rules = "0,1,2,3,4,5,6,7,8,9";

    var tmprules = rules;
    n = 1;
    while (tmprules.indexOf(",") != -1) {
        tmprules = tmprules.substring(tmprules.indexOf(",") + 1, tmprules.length);
        n++;
    }
    this.rules = new makeArray(n);
    n = 0;
    while (rules.indexOf(",") != -1) {
        var tmpstr = rules.substring(0, rules.indexOf(","));
        this.rules[n] = tmpstr;
        rules = rules.substring(rules.indexOf(",") + 1, rules.length);
        n++;
    }
    this.rules[n] = rules;
    return this;
}