title: Stripe custom checkout not Posting
body: <p>Can anyone assist as to why this is not posting to booking/charge upon completion of input to the checkout pop up window?</p>
  
  <p>The simple checkout example posts fine, I am new to js so I don't quite understand the flow of the commands.</p>
  
  <pre><code>&lt;form action="/booking/charge" method="post"&gt;
  &lt;script src="https://checkout.stripe.com/checkout.js"&gt;&lt;/script&gt;
  &lt;button id="customButton"&gt;Purchase&lt;/button&gt;
   &lt;script&gt;
  var handler = StripeCheckout.configure({
    key: 'pk_test_xxxxxxxxxxx',
    image: 'https://stripe.com/img/documentation/checkout/marketplace.png',
    locale: 'auto',
    token: function(token) {
      // You can access the token ID with `token.id`.
      // Get the token ID to your server-side code for use.
    }
  });
  
  document.getElementById('customButton').addEventListener('click', function(e) {
    // Open Checkout with further options:
    handler.open({
      name: 'xxxx',
      email: "test@test.com",
      description: '2 widgets',
      currency: 'gbp',
      amount: 350
    });
    e.preventDefault();
  });
  
  // Close Checkout on page navigation:
  window.addEventListener('popstate', function() {
    handler.close();
  });
  &lt;/script&gt;    
  &lt;/form&gt;
  </code></pre>