Good book to read on Javascript and Ajax....

I got this book to help me study and integrate ajax and javascripts - this is the website JavaScript: The Definitive Guide, Fifth Edition. I got this book over a year ago and just now started looking at it. Now that I am taking a class that uses the book features, looks like a good secondary book to have. If you are interested, you might be able to get it at a much lower price on half.com. That is where I buy most of my books from.