Client Side Calculator

One of the elementry tutorials in a subject I am studying was to create a client side calculator using on HTML, CSS and JavaScript. While I already had the capibilities to create this application it a great refresher and I enjoyed being able to do something quickly without the need to do a great deal of looking up. I thought I would share it for any people who are beginning to use javascript. I have commented all of the files and believe this is a great activity to complete when beginning to learn the scripting language. Obviously JavaScript is vital in any webdeveloper's tool box. Especially with the emergence of HTML5 which has many aspects that are heavily reliant on JavaScript. Find the source code below.