Who  has any probrem with brightness for the laptop netbook Samsung N150 please try this. Insyaallah your brightness problem will solve.

Go to terminal and type:

sudo add-apt-repository ppa:voria/ppa
sudo apt-get update && sudo apt-get upgrade
sudo apt-get install samsung-tools samsung-backlight
sudo reboot

Tara........

Credit to https://bugs.launchpad.net/ubuntu/+source/udev/+bug/574250