He is currently principal front end engineer for the Yahoo! homepage and is a contributor to the Yahoo! User Interface (YUI) library, having written the Cookie Utility, Profiler, and YUI Test. Nicholas is the author of Professional JavaScript for Web Developers and a co-author on Professional Ajax, and has contributed to other books. He has also written several online articles for WebReference, Sitepoint, and the YUI Blog. Nicholas regularly gives talks about Web development, JavaScript, and best practices. He has given talks at companies such as Yahoo!, LinkedIn, Google, and NASA, and conferences such as the Ajax Experience, the Rich Web Experience, and Velocity. Through his writing and speaking, Nicholas seeks to teach others the valuable lessons he