brightness of dell insipirion laptop

when i try to increase or decrease the brightness of my laptop monitor, it flickers and then either remains at the top bright level or the lowest bright level. i cannot set any value between them.

BTW i am trying to set the brightness from my keyboard,

what should i do to set the brightness of the lcd. i remember doing so very long time ago, but could not remember how i did it.

how do i change the brightness of the monitor in suse? (no reply ? :frowning: )