Ajax is no longer an experimental approach to website development, but the key to building browser-based applications that form the cornerstone of Web 2.0. ''Head First Ajax'' gives you an up-to-date perspective that lets you see exactly what you can do - and has been done - with Ajax. With it, you get a highly practical, in-depth, and mature view of what is now a mature development approach. Using the unique and highly effective visual format that has turned ''Head First'' titles into runaway bestsellers, this book offers a big picture overview to introduce Ajax, and then explores the use of individual Ajax components - including the JavaScript event model, DOM, XML, JSON, and more - as it progresses.You'll find plenty of sample applications that illustrate the concepts, along with exercises, quizzes, and other interactive features to help you retain what you've learned.''Head First Ajax'' covers: the JavaScript event model; making Ajax requests with XML HTTP REQUEST objects; the asynchronous application model; the Document Object Model (DOM); manipulating the DOM in JavaScript; controlling the browser with the Browser Object Model; XHTML Forms; POST Requests; XML Syntax and the XML DOM tree; XML Requests & Responses; JSON - an alternative to XML; Ajax architecture & patterns; and the Prototype Library.The book also discusses the server-side implications of building Ajax applications, and uses a ''black box'' approach to server-side components. ''Head First Ajax'' is the ideal guide for experienced web developers comfortable with scripting - particularly those who have completed the exercises in ''Head First JavaScript'' - and for experienced programmers in Java, PHP, and C# who want to learn client-side programming.