If I am using many js files in my project and get JavaScript errors in IE 6 or 7's status bar, then how can I trace, find and solve those errors in Firefox? I know how to trace a problem in [IE with visual studio](http://www.berniecode.com/blog/2007/03/08/how-to-debug-javascript-with-visual-web-developer-express/) but can we identify area of problem using Firefox?