The first thing to do is grab the mootools library from the site and link it in your web page. You can select different components with mootools, but if you grab the whole thing you can start to play with whatever you want. Put this line of code in the head section of your web page.
For this example I want the highlight to occur when the page has finished loading. So I use the window.addEvent function to add an action for the 'domready' event to the window object of the page.