Build a very simple cash register application. It should have/do the following:
- Include clickable buttons/links at the top that add to a section on the left-hand side.
- As you add each item, the tax and total should immediately change.
- Your items should be grouped -- that is, if you order two cheeseburgers, you should not have two lines but instead a single one that shows the total of the two cheeseburgers.
