Here's an easy question, how shutdown debian?

[André Bell <debian2@one-click.com>]

Everytime I restart my debian pc after having turned it off debian tells me
at bootup that devices were not unmounted properly. I don't use any
commands to shutdown debian, I just use the on/off switch when I'm
finished.  Apparantly that is a bad idea.

I'm guessing there must be a way to get debian to shutdown properly so I
don't have to wait for everything to uncompress and unmount before it can
boot up again(?).

If so, what is the command to shutdown?  Or is it simply cntrl/alt/del to
cause debian to stop everything from running and then turn it off at memory
checking?  That's the only way I know how to avoid error messages that say
the system was not properly unmounted.

Thanks

Andre'