Changing screen brightness

I have a hp pavilion dv6 with xubuntu installed. however there isn't a way to change the screen brightness, i tried the fn plus scroll keys to no avail, any ideas?

Package name is xfce4-power-manager-plugins. Solved my brightness problem in xubuntu 10.04.2.

echo 1 | sudo tee /sys/class/backlight/acpi_video0/brightness

You can change:

• Brightness from 1 to 10.
• acpi_video0 or acpi_video1

XFCE has a panel applet for changing brightness, I don't remember if it's installed, so search in packages (e.g. in synaptic) for XFCE and brightness. Then right-click on the panel to add it.

1. Open your terminal
2. Type sudo apt-get install xfce4-power-manager-plugins
3. Enter your password and press y key to continue
4. Right-click on the panel, Panel-> Panel Preferences...
5. Come to the Items tab, click on Add new items button (+) and search for Power Manager Plugin
6. Select it and click on the Add button