See the demo
The organization wanted to have a shopping cart for their members-only merchandise, but they did not have database support at their web host,so the solution I pursued was to develop their shopping cart entirely in object-oriented Javascript.
The javascript works in a data-island, and contains objects for the customer's shopping basket. All of the processing is done on the client side, which makes it very fast.
The screens in the checkout area are updated by modifying the DOM, and the order is submitted by serializing a JSON structure and sending it to the server. The server would then email the order to the person who would fulfill it.
This programming approach has come to be called AJAX, of course at the time I did it, it had no such name.
[Recently I updated the JS object to be the more modern closure-style of a class.
See the demo