using crt and lcd on Inspiron 710m

[Mauricio Vergara Ereche]

Hi!

I've been trying to do some presentations on my dell inspiron 710m which 
runs FC5, and I noticed that I can't use the Fn+F8 key to work... but in 
WinXP it does.

So I tried to use the references of this page:
http://www.astro.umd.edu/~teuben/linux/laptop-display.html
but that didn't work for me :-(

Anybody have been lucky with this?
Any suggestions?

Thanks in advance

Mauricio