OK, I'm using: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:220.127.116.11) Gecko/20071025 Firefox/18.104.22.168
And when I enter in the code exactly as I see it in the book, it doesn't work. If you simply switch to IE7, it works fine. I was half way through page 42 of the second edition:
Any ideas what might be preventing it from working? It shows me the alert("Got Response!") bit, but nothing after that.