I explain!!! Exec ever put down my computer

From: Alexander (alexander_at_edem.g12.br)
Date: 05/05/04 

Date: 5 May 2004 10:28:34 -0700

No!!! I forgot something !!!!!!!!!!!

This code reset my computer when I load the script!!!

Just load! I don't click in anything. I just load the script and my
computer turn off!!

OK??

Sorry for confusion.

Now, can you explain why!!

THanks!
Alexander
Brazil

MY CODE:
========================================================================

Hi all!

I have one script and when I "play" this script my computer is halted.

I know the solution (just one list before exec command), but I want
know why this thing happen.

Why "exec" put down my computer when that don't have one "list["
command before?

It's very strange for me!

Sorry again and again for my english!
Thanks!
Alexander
Brazil

#!/usr/bin/wish

wm geometry . -0+0
button .haltest -text Desligar -fg gray -bg white -command {
exec shutdown -h now
}

pack .haltest -side left