Download the ZIP to get started.
To save you time, the HTML and CSS are all written for you. Just open up the "script.js" file and start writing the program. You'll see there's already a little code to get you started.
Note: the strike-through and dimming of the is being done entirely with CSS. But in order for you to take advantage of the CSS rule that does it, you need to create a very specific markup for each item: