Two books live on my desk when I'm working on Web pages with client-side scripting: David Flanagan's JavaScript: The Definitive Guide, 5th Edition (O'Reilly, 2006, 994 pp., $49.99, ISBN 978-0-596-10199-2), and Danny Goodman's Dynamic HTML: The Definitive Reference, 3rd Edition (O'Reilly, 2007, 1307 pp., $59.99, ISBN 978-0-596-52740-2). They're both huge books, and their content overlaps substantially, They’re both huge books, and their content overlaps substantially, but they both keep earning their spots. I reach for Flanagan if the question in my mind is primarily about some aspect of JavaScript, and for Goodman if the question is primarily about some aspect of HTML, XHTML, CSS or the Document Object Model.Flanagan has two tutorial sections. Part I explains core JavaScript, and Part II explains browser DOM scripting. I read them once: they were nice. I don’t think I have looked at them again since the latest edition of the book arrived.It’s the reference sections of the two books that I return to over and over. Flanagan Part III is a complete reference to core JavaScript 1.5 and ECMAScript version 3. Flanagan Part IV is a reference for client-side JavaScript. It’s notoriously difficult to write sophisticated cross-browser JavaScript: Flanagan helps you figure out what to do when, for example, an area is outside the DOM Level 2 standard and implemented differently in IE and Firefox.Goodman Part I is a Dynamic HTML reference, with five subsections: HTML and XHTML, DOM, Events, Style Sheets, and core JavaScript. Part II has cross references to attributes, properties, methods and events. Part III has tables of color names, HTML character entities, keyboard event character values, editable content commands, HTML/XHTML DTD support, and a cross reference to Mozilla-based browser version numbers. Software Development