My Ubuntu 12.04 is still running old version of firefox browser. Other than that, Facebook always having script problem on my firefox, thus I try to update it.
To install/update Firefox is very simple, just follow below 3 steps by installing PPA. Other than that, u can only directly download from Mozilla website.
1. Add Firefox 20 repository
$ sudo add-apt-repository ppa:ubuntu-mozilla-security/ppa
2. Update system
$ sudo apt-get update
3. Install firefox
$ sudo apt-get install firefox
TaDa, my new Firefox browser~~~