anchor.diff:  
           var handler = StripeCheckout.configure({
             key: '<%= ENV["STRIPE_API_PUBLIC_KEY"] %>',
  -          image: 'http://www.gravatar.com/avatar/<%= admin_hash %>.jpg?s=120',
  +          image: '//www.gravatar.com/avatar/<%= admin_hash %>.jpg?s=120',
             token: function(token) {
               updateButton('sending');
               setEnabled($('input, form'), false);
  
positive.code:         checkFormReady();
  
          var updateGravatar = function() {
            $("#userAvatar").attr("src","http://www.gravatar.com/avatar/" + md5($("#email").val()) + ".jpg?s=120&d=blank");
          }
          $('#email').on('change input', updateGravatar);
          updateGravatar();
  
negative.code:         Powered by <a href="https://github.com/lord/cashin">Cashin</a>
        </div>
      </main>
      <script src="//code.jquery.com/jquery-2.1.4.js"></script>
      <script src="/md5.js"></script>
      <script src="https://checkout.stripe.com/checkout.js"></script>
      <script>
  