Upgrade PHP from 5.3 to 5.4 on ubuntu 12.04

There are simple steps to upgrade your PHP version from 5.3 to 5.4 .

1)  Add the below repository in your system
      sudo add-apt-repository ppa:ondrej/php5-oldstable

2) Run the below command to update your packages
     sudo apt-get update

3)  Install the python-software-properties with below command, that need to be  
      necessary to add a package repository:
      sudo apt-get install python-software-properties

4) Run the below command now to upgrade version and follow the instructions .
     sudo apt-get install php5