Best book to learn JavaScript?

I get in trouble every time I answer this sort of question, but here I go again.
The real problem with learning JavaScript is it should not be your first environment. Before you can learn JavaScript, you need to be fluent in HTML / XHTML and CSS. You can't rely on a tool like Dreamweaver or Expression Web. You need to be able to build Valid XHTML strict code with CSS as the primary layout engine.
This is important because HTML / XHTML serves as the user interface layer for JavaScript, and your JS code will be interacting with and manipulating the HTML code on the fly.
Many people who begin with JavaScript start without adequate preparation in XHTML and CSS, and find themselves frustrated.
I've actually written several books about this topic, and (at the risk of being self-serving) want to introduce two of them to you.
If you need an overview of all web development topics from the beginning, take a look at
HTML / XHTML / CSS All in One for Dummies. This book is actually eight books in one, allowing you to pick the technologies you want to focus on. It begins at the very beginning, making sure you have a solid grounding in XHTML and CSS before you work on JavaScript code. If you're already comfortable with HTML and CSS, you can go straight to the JavaScript mini-book. Once you've got a handle on JavaScript, you can move onto the server with PHP, or look into the emerging AJAX environment. All the mini-books are written to work together, so you'll get one consistent representation all the way from the absolute beginning to advanced content management systems with databases and PHP.
I focused entirely on open-source technologies throughout the book, so you won't need to purchase anything else. Everything you need is included on the web site and/or the CD-ROM.
If you run into any problems, you can always write to me, and I'll be happy to help.
If you just want to focus on JavaScript and AJAX, I've written a newer book that takes these topics a little deaper:
JavaScript and AJAX for Dummies is similar to the All in One book, but it spends more effort on the JavaScript side.
I'm actually integrating much of the JavaScript book into the second edition of the All in One, but that process is ongoing, so you'll probably want something before that book comes out.
You can get lots of examples from my book site. Every program in the books is available there, as are links to all the other software and some other fun stuff! Please stop by!

I find the O'Reilly books a great introduction to web-programming. I've put a link to the JavaScript book below.
http://www.amazon.co.uk/gp/product/1565922344?ie=UTF8&tag=1189&linkCode=as2&camp=1634&creative=19450&creativeASIN=1565922344