[Solved ] Ubuntu 11.10 automatic brightness setting

This time I want to explain about how to make ubuntu 11.10 automatic set the brightness when its start. I have a problem after installing ubuntu 11.10, the brightness setting always change after I restarted the computer.

I have this solved from the internet, first you should go to terminal / console.

sudo su
[your root password]

gedit /etc/rc.local

now you must edit this document, first you should add # before exit 0 , like this :

#exit 0

then you add this command echo 9 > /sys/class/backlight/acpi_video0/brightness under #exit 0, like this :

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.

#exit 0

echo 9 > /sys/class/backlight/acpi_video0/brightness

then restart your computer.
good luck, sorry my english is not too good :)