Introduction

avaScript is a compact, object-based scripting language for developing client and server Internet applications. Netscape Navigator interprets JavaScript statements embedded in an HTML page, and LiveWire enables you to create server-based applications similar to Common Gateway Interface (CGI) programs. This book describes the JavaScript language and its use in Navigator. For information on developing server-based JavaScript applications, see the LiveWire Developer's Guide.

What's new in Navigator 3.0

JavaScript for Navigator 3.0 has a rich set of new features. Appendix F, "Features added after version 1," lists the new objects, properties, arrays, methods, functions, event handlers, operators, and other features.

What you should already know

This book assumes you have some basic background, including

A general understanding of the Internet and the World Wide Web (WWW).
Good working knowledge of HyperText Markup Language (HTML).

Some programming experience with a language such as C or Visual Basic is useful, but not required.

How to use this book

This book is divided into three parts:

Part 1, "Using JavaScript in Navigator," introduces JavaScript and describes its use in Navigator. It covers the main features of client JavaScript and touches on some advanced topics.
Part 2, "The JavaScript languag," describes the syntax and semantics of the JavaScript language itself and is applicable to both client-side and server-side JavaScript. It also describes JavaScript's built-in String, Math, and Date objects, built-in functions, and statement syntax.
Part 3, "Reference," is a comprehensive, alphabetical reference for Navigator JavaScript. It includes a chapter on JavaScript statements and one for all objects, properties, and methods in Navigator JavaScript.

If you are new to JavaScript, start with Chapter 1, "Getting started" to start scripting your own pages immediately. Then continue with the chapters in Part 1, to learn more about JavaScript in Navigator. You may find it useful to skim the material in Part 2, particularly Chapter 8, "Object model." Use the reference material in Part 3 as necessary for details on specific topics.

If you are already familiar with JavaScript in Navigator, skim the material in Part 1, paying particular attention to the chapters that discuss more advanced topics: Chapter 3, "Using windows and frames" and Chapter 5, "Advanced topics." You can then use the reference material as needed.

If you are a LiveWire application developer, use the material in Part 1 to familiarize yourself with the basics of JavaScript. Then read Part 2 for a more in-depth look at the JavaScript language. All the material in Part 2 is applicable to LiveWire JavaScript. You need to read only material on client JavaScript if you want to incorporate only client functionality into your applications.

Document conventions

Netscape Navigator runs on many different operating systems; the information here applies to all versions. File and directory paths are given in Windows format (with backslashes separating directory names). For Unix versions, the directory paths are the same, except slashes instead of backslashes separate directories.

Figures that show screens were created using Windows NT. Screens on your platform may look different.

This book uses Uniform Resource Locators (URLs) of the form

http://server.domain/path/file.html

In these URLs, server represents the name of the server on which you are running LiveWire, such as "research1" or "www," and domain represents your Internet domain name, such as "netscape.com" or "uiuc.edu." If you have configured your proxy, you might not need to specify your domain name when the client itself is within the domain. In general, italic items in URLs are variables, and items in normal Courier font are literals.

This book uses the following typographical conventions:

File and directory names are shown in fixed-pitch font, for example, c:\javascript\samples\world\hello.html.
JavaScript method and function names are shown in boldface without any parentheses; for example, write and alert.
JavaScript object and property names are shown in italics; for example, document.title and Date object.

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