Adjusting Brightness/Contrast in Laptop

Hai everybody...

I am using a Laptop (Compaq Presario C 765 TU Model). In Windows, I can adjust Contrast and Brightness properties by using software (desktop right click menu allows options for this).

How can I do this in Ubuntu... (I'm using Ubuntu 9.04 with KDE 4.2.2)

Please help to solve my problem...

google: kde luminosity applet

google: kde luminosity applet ---->http://klcddimmer.sourceforge.net/