The Yahoo! User Interface (YUI) Library is a set of utilities and controls, written in JavaScript, for building richly interactive web applications using techniques such as DOM scripting, DHTML, and AJAX. The YUI Library also includes several core CSS resources. All components in the YUI Library have been released as open source under a BSD license and are free for all uses. This book covers all released components whether utility, control, core file, or CSS tool. Methods of the YAHOO Global Object are used and discussed throughout the book. The basics of each control will be presented, along with a detailed example showing its use to create complex, fully featured, cross-browser, Web 2.0 user interfaces. Besides giving you a deep understand of the YUI library, this book will expand your knowledge of object-oriented JavaScript programming, as well as strengthen your understanding of the DOM and CSS. You will learn to create a number of powerful JavaScript controls that can be used straight away in your own applications.