[CentOS] X11 virtual screens on centos 5

Wed Sep 5 01:40:09 UTC 2007
Jerry Geis <geisj at pagestation.com>

When the you select an X11 virtual screen (1 of 4) with the mouse on 
default centos 5
what command gets executed to show screen 1, screen 2 etc...

Basically, I want to have a command or know the command
to     execute to show the desired virtual X11 screen.