12.0.2. Firebug

Firebug^[1] is an extremely powerful extension for Firefox and a must-have tool for doing Ajax work. It lets you inspect Ajax requests and probe the DOM of the page extensively, even letting you change elements and CSS styles on the fly and see the results on your browser screen. It also has a very powerful JavaScript debugger that you can use to set watch expressions and breakpoints.

^[1] The first step to getting the Firebug plugin for Firefox is to visit http://www.getfirebug.com

Firebug also has an interactive console, which allows you to experiment with JavaScript in the browser just as you would use irb in Ruby. In some cases, the code samples in this chapter are copied from the Firebug console, which has a >>> prompt.