The process of finding and fixing bugs is called debugging and is a normal part of the development process. Other browsers like Firefox, Netscape, and Mozilla send error messages to a special window called the JavaScript Console or Error Console.
Unfortunately, since these browsers give no visual indication when an error occurs, you must keep the Console open and watch for errors as your script executes.
To debug JavaScript using Firefox, follow the procedure given below −
To view the console, Open Menu→ select Web Developer.
Now select Web Console from the following −
The Web Console window is visible now −
