Use 4 spaces for indentation instead of 2

I think 2 spaces for indentation is too little. By using 4 spaces it becomes more obvious that a piece of code is indented and it looks ugly when there's too many indentation levels -- which I also think should be avoided.

I would also be ok using tabs -- just pick one of those and stick with it.
Use strict

Some reasons why one should use 'use strict'
parseInt radix parameter

One should always provide the radix parameter to parseInt
Merge pull request #1 from brpinto/master

Some Coding Style Suggestions