JavaScript Tutorial

F or nearly 20 years, I have written the books I wished had already been written to help me learn or use a new technology. Whenever possible, I like to get in at the very beginning of a new authoring or programming environment, feel the grow- ing pains, and share with readers the solutions to my struggles. This Gold edition of the JavaScript Bible represents knowledge and experience accumulated over five years of daily work in JavaScript and a constant monitoring of newsgroups for ques- tions, problems, and challenges facing scripters at all levels. My goal is to help you avoid the same frustration and head scratching I and others have experienced through multiple generations of scriptable browsers. While previous editions of this book focused on the then-predominant Netscape Navigator browser, the swing of the browser market share pendulum currently favors Microsoft Internet Explorer. At the same time, Netscape has accomplished the admirable task of reinventing its own browser in light of rapidly advancing industry standards. As a result of both of these trends, this massively revised and expanded Gold edition treats both brands of browsers as equals as far as scripters are concerned. You hear my praise and dismay at various scripting features of both browser families. But empowering you to design and write good scripts is my pas- sion, regardless of browser. Therefore, the book contains details about proprietary and standard implementations to equip you to choose the development path that best fits your content’s audience. If you detect any bias of mine throughout this book, it is a desire, where possible, to write scripts that work on as many browsers