mratzloff

var validateCreditCard = function(field, rules, i, options) {
  var valid = false,
  cardNumber = field.val().replace(/ +/g, "").replace(/-+/g, "");

  var numDigits = cardNumber.length;
  if (numDigits >= 14 && numDigits <= 16 && parseInt(cardNumber) > 0) {
    var pos = 1;
    var luhn = "";
    for (var i = numDigits - 1; i >= 0; i--) {
      var digit = parseInt(cardNumber.charAt(i));