validateCreditCard.js
Summary
No overview generated for 'validateCreditCard.js'
Method Summary
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static Object
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isLuhnNum(argvalue)
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static Object
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luhnCheck(cardNumber)
Checks whether a given credit card number has a valid Luhn checksum.
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static Object
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validateCreditCard(form)
Check to see if fields are a valid creditcard number based on Luhn checksum.
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function validateCreditCard(form) {
var bValid = true;
var focusField = null;
var i = 0;
var fields = new Array();
oCreditCard = eval('new ' + retrieveFormName(form) + '_creditCard()');
for (x in oCreditCard) {
if ((form[oCreditCard[x][0]].type == 'text' ||
form[oCreditCard[x][0]].type == 'textarea') &&
(form[oCreditCard[x][0]].value.length > 0) &&
form[oCreditCard[x][0]].disabled == false) {
if (!luhnCheck(form[oCreditCard[x][0]].value)) {
if (i == 0) {
focusField = form[oCreditCard[x][0]];
}
fields[i++] = oCreditCard[x][1];
bValid = false;
}
}
}
if (fields.length > 0) {
focusField.focus();
alert(fields.join('\n'));
}
return bValid;
}
function luhnCheck(cardNumber) {
if (isLuhnNum(cardNumber)) {
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 == 0) return false;
if (sum % 10 == 0) return true;
};
return false;
}
function isLuhnNum(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;
}
Copyright ¬ 2000-2005 - Apache Software Foundation
Documentation generated by
JSDoc on Wed Nov 16 02:51:00 2005