1 files changed, 19 insertions, 0 deletions
diff --git a/epirts.js b/epirts.js
index 3db67d0..7053626 100644
--- a/epirts.js
+++ b/epirts.js
@@ -44,6 +44,25 @@ var Stripe = Epirts = (function() {
 		pub.validateCardNumber = function(number) {
 		};
 
+		pub.luhnCheck = function(number) {
+			var i;
+			var digit;
+			var sum;
+
+			number += '';
+			sum = 0;
+			for (i = 0; i < number.length; ++i) {
+				digit = number.charAt(number.length - 1 - i);
+				digit = parseInt(digit);
+				digit *= i % 2 + 1;
+				if (digit > 9) {
+					digit -= 9;
+				}
+				sum += digit;
+			}
+			return sum % 10 === 0;
+		};
+
 		pub.validateExpiry = function(month, year) {
 		};