linux xubuntu 6.1 computer

[Don and/or Mila Trombley]

I am wondering if there is a built-in Linux Xubuntu shut down command 
sequence which would facilitate shutting down completely the Machine 
after closing My session, after a specified period of inactiivity?
Xubuntu  "logs out, or Shuts down" without shutting down the Packard 
Bell Synera computer which has a Pentium 2 processor. . . I have to 
manually shut it down.