text: $(function() {
  
      var owner = $('#owner');
      var cardNumber = $('#cardNumber');
      var cardNumberField = $('#card-number-field');
      var CVV = $("#cvv");
      var mastercard = $("#mastercard");
      var confirmButton = $('#confirm-purchase');
      var visa = $("#visa");
      var amex = $("#amex");
  
      // Use the payform library to format and validate
      // the payment fields.
  
      cardNumber.payform('formatCardNumber');
      CVV.payform('formatCardCVC');
  
  
      cardNumber.keyup(function() {
  
          amex.removeClass('transparent');
          visa.removeClass('transparent');
          mastercard.removeClass('transparent');
  
          if ($.payform.validateCardNumber(cardNumber.val()) == false) {
              cardNumberField.addClass('has-error');
          } else {
              cardNumberField.removeClass('has-error');
              cardNumberField.addClass('has-success');
          }
  
          if ($.payform.parseCardType(cardNumber.val()) == 'visa') {
              mastercard.addClass('transparent');
              amex.addClass('transparent');
          } else if ($.payform.parseCardType(cardNumber.val()) == 'amex') {
              mastercard.addClass('transparent');
              visa.addClass('transparent');
          } else if ($.payform.parseCardType(cardNumber.val()) == 'mastercard') {
              amex.addClass('transparent');
              visa.addClass('transparent');
          }
      });
  
      confirmButton.click(function(e) {
  
          e.preventDefault();
  
          var isCardValid = $.payform.validateCardNumber(cardNumber.val());
          var isCvvValid = $.payform.validateCardCVC(CVV.val());
  
          if(owner.val().length < 5){
              alert("Wrong Card owner name");
          } else if (!isCardValid) {
              alert("Wrong card number");
          } else if (!isCvvValid) {
              alert("Wrong CVV");
          } else {
              window.location.href="thankyou.html"
          }
      });
  });
  