Possible Duplicate:
How can I make shutdown not require admin password?
When I'm logged in on my own account and try to do Restart or Shutdown from the "Power" menu, while others are also logged in, all that happens is that I get logged out. Everyone else stays logged in and the computer does not shut down. If I try to then do "Shutdown" or "Restart" from the Login screen, nothing happens.
In case it matters, in Users Settings, my Account Type is "Administrator", but everyone else is "Desktop User".
You can enable that by using PolicyKit. It used to be installed by default, but it no longer is. There is a setting to allow some users to shut down the system while other users are logged in. Please remember that you will delete all of the other users unsaved work, so you shouldn't do this even if you can.
This should work :
or:
depending what do you need.