Enabling a strict JavaScript logging in Firefox

I'm reading the great "Object-Oriented JavaScript: Create scalable, reusable high-quality JavaScript applications and libraries" book (to be honest, I'm finding it really better than the more know "JavaScript: The Good Parts" if you want to learn something new about JavaScript programming).

One of the great tip you read in the first pages is about how enable a better logging of warning in the JavaScript syntax in Firefox.

• Open Firefox and go to the about:config page
• Search the entry called javascript.options.strict
• Set this to true

From now your Firefox will log a lot more warning in the console window (not talking of Firebug, simply the standard Firefox console). It's someway like a JSLint integrated helper!