#! code

Firebug is by far the best JavaScript debugging plug-in available for Firefox. I have been stuck on a few problems in the past and Firebug has usually provided me with a reason as to why things are going wrong. In fact when developing for other browsers (like Internet Explorer) I can feel a little blind as there are no debugging tools with the power and features of Firebug. It can allow you to stop JavaScript execution at any time using breakpoints.