This book will teach you how to create interactive Web sites from the simplest order form through to complex secure e-commerce sites. What’s more, you’ll learn how to do it using Open Source technologies. This book is aimed at readers who already know at least the basics of HTML and have done some programming in a modern programming language before, but have not necessarily programmed for the Internet or used a relational database. If you are a beginning programmer, you should still find this book useful, but it might take you a little longer to digest. We’ve tried not to leave out any basic concepts, but we do cover them at speed. The typical reader of this book is someone who wants to master PHP and MySQL for the purpose of building a large or commercial Web site. You might already be working in another Web development language; if so, this book should get you up to speed quickly. We wrote this book because we were tired of finding books on PHP that were basically a function reference. These books are useful, but they don’t help when your boss or client has said “Go build me a shopping cart.� We have done our best to make every example useful. Many of the code samples can be directly used in your Web site, and many others can be used with minor modifications.