Howto blank main screen when viewing on second screen?

[lbottecchia]

Hi to all!
I'm using vlc to view movies on my projector, connected to my mac with the mini-vga port.
I choose the second peripheral on the video menu of vlc, open the movie and choose full screen, and all work fine.
The only thing is that the main monitor doesn't blank and it's quite disturbing cos is very bright.
Other software like quicktime automatically does this, but I prefer vlc and can't find any option in the preferences or in this forum.
Any suggestion?

Thanks in advice!

vlc 0.8.6c, iMac with Mac OS X 10.4.10