The book's example scripts include one that sorts a data table according to the user's search queries, a form validation script, a script that shows form fields only when the user needs them, a drop-down menu, and a data retrieval script that uses simple Ajax and shows the data in an animation.
In essence, it reminds me of how I learned to work on the web in the first place: careful examination of other people’s work. At its best, this book is a clearly annotated view source of Koch’s projects. It’s a comprehensive exploration of Koch’s thoughts about the problems he’s run into (problems that you’ll run into, too), how he approached them, and ultimately how he’s solved them." -- Mike West, Managing Editor, Digital Web Magazine