If you already have a background in HTML and JavaScript then you are ready for this text. The author does a nice job of introducing the concepts behind Dynamic HTML. Usually this type of book would be enormous because the subject is complex (see the O'Reilly text for a really big book on this subject). This book, however, covers the most common things you can do with Dynamic HTML without going overboard on the details. The book is also fun to read and, most importantly, there isn't a single error in any of the code listings when run on a modern browser. Not many books can make that claim these days.