If you've found that creating Web pages was a bit too much like formatting a document and too little about creating interactivity, then Javascript can help you. Javascript hugely extends the functionality of HTML by working with your web browser's object model. If you'd quickly like to develop an online quiz, a puzzle with time functions, manipulate the look and feel of browser windows, display alerts on click and everything else that you've seen but couldn't figure out how to do, then get your teeth into this. Javascript.com contains hundreds of free scripts that you can cut and paste into your code. Should you ever get stuck and need advice, then there is a very busy forum to quickly get answers from experts from around the world.