Innovative JavaScript behaviors are the hallmark of Web 2.0 interface designs. Visit Apple, Facebook, Microsoft, or any other web titan, and you will find JavaScript implementations providing a smooth, tactile, engaging web experience. Knowledge of JavaScript is essential for developing modern, interactive, sticky web sites, but many beginners are put off by the daunting need to learn a programming language before they can achieve anything. This book takes a practical approach by showing you how to use JavaScript in simple stages, starting with the basics of storing and manipulating data and moving on to reacting to events and using JavaScript to alter CSS and HTML on the fly. It assumes no prior knowledge of JavaScript, and avoids bombarding you with unnecessary technical details. At the same time, it explains the main points and acts as a reference that you can come back to when you need to refresh your memory. More advanced concepts are introduced gradually, so that by the end of the book you'll have a solid understanding of all the main aspects of JavaScript. Particular attention is paid to debugging and avoiding common beginners' pitfalls, enabling you to create web sites that not only look good, but are dynamic and exciting for visitors.