v Copyright Library of Congress Cataloging-in-Publication Data Barrett, Daniel J. Essential JavaScript for Web professionals / Dan Barrett, Dan Livingston, Micah Brown. p. cm -- (Prentice Hall essential Web professionals series) ISBN 0-13-013056-7 (pbk.) 1. JavaScript (Computer program language) I. Livingston, Dan. II. Brown, Micah. III. Title. IV. Series. QA76.76.J39 B37 1999 005.2\q762--dc21 99-16801 CIP Copyright Information © 1999 Prentice Hall PTR Prentice-Hall, Inc. Upper Saddle River, NJ 07458 Prentice Hall books are widely used by corporations and government agencies for training, mar- keting, and resale. The publisher offers discounts on this book when ordered in bulk quantities. For more information, contact: Corporate Sales Department, Phone: 800-382-3419; Fax: 201-236-7141; E-mail: <corpsales@prenhall.com>; or write: Prentice Hall PTR, Corp. Sales Dept., One Lake Street, Upper Saddle River, NJ 07458. All rights reserved. No part of this book may be reproduced, in any form or by any means, without permission in writing from the publisher. Printed in the United States of America 10 9 8 7 6 5 4 3 2 1 Prentice-Hall International (UK) Limited, London Prentice-Hall of Australia Pty. Limited, Sydney Prentice-Hall Canada Inc., Toronto Prentice-Hall Hispanoamericana, S.A., Mexico Prentice-Hall of India Private Limited, New Delhi Prentice-Hall of Japan, Inc., Tokyo Prentice-Hall (Singapore) Pte. Ltd., Singapore