Inserted DVD disc not recognized

I was trying to watch a DVD on my Ubuntu laptop, however, whenever I insert the disc, the CD/DVD drive icon on the Computer pane disappears, seems that it cannot detect what type of disc was inserted.

I am running on Ubuntu 12.04 LTS and new to these things as I used to be comfortable with Windows doing the things for me.

IMMEDIATE HELP WILL BE APPRECIATED as I just borrowed this DVD from a mate who allowed me to watch it until I finish the episodes inside the CD.

You may need to add the correct codecs for DVD Playback, They do not come with the Live Ubuntu CD

First Install the Medibuntu Repositories Medibuntu repository provides all the playback and encoding capabilities that most Windows and Mac systems contain, but which Ubuntu’s creators decline to include by default in their systems, due to licensing restrictions and a lack of open-source code for those features. If you just want to get AAC playback, copyright DVDs playing, and newer versions of all the audio, video, and font files, load Medibuntu into your system.

Open your Terminal (Ctrl-Alt-T), copy and paste these 3 lines (one at a time):

sudo wget --output-document=/etc/apt/sources.list.d/medibuntu.list http://www.medibuntu.org/sources.list.d/$(lsb_release -cs).list && sudo apt-get --quiet update && sudo apt-get --yes --quiet --allow-unauthenticated install medibuntu-keyring && sudo apt-get --quiet update
sudo apt-get -y update && sudo apt-get -y upgrade
sudo apt-get install app-install-data-medibuntu apport-hooks-medibuntu

Then

If you are running a 32-bit version of Ubuntu, copy and paste in Terminal:

sudo apt-get install w32codecs libdvdcss2
sudo apt-get install libdvdnav4
sudo apt-get install libdvdread4
sudo /usr/share/doc/libdvdread4/./install-css.sh

If you are running a 64-bit version of Ubuntu, copy and paste in Terminal:

sudo apt-get install w64codecs libdvdcss2
sudo apt-get install libdvdnav4
sudo apt-get install libdvdread4
sudo /usr/share/doc/libdvdread4/./install-css.sh

Once Completed you will be able to play DVDs.