Hi all, and please be patient with a fresh guy

I'm an owner of a Toshiba Satellite L300, with some problems under ubuntu, where the most annoying is that the combination of FN+function keys to control volume or brightness are not working.

Since internet is full of toshiba related tips that simply don't work (maybe because too old or the hardware too different), I would ask another owner of this notebook to tell me how could I make the FN combination work.

Thanks in advance.