DESCRIPTION
       Tk::ExecuteCommand runs a command yet still allows Tk
       events to flow.  All command output and errors are dis-
       played in a window.

       This ExecuteCommand mega widget is composed of an LabEntry
       widget for command entry, a "Do It" Button that initiates
       command execution, and a ROText widget that collects com-
       mand execution output.

       While the command is executing, the "Do It" Button changes
       to a "Cancel" Button that can prematurely kill the execut-
       ing command. The kill_command method does the same thing
       programmatically.

Steve Lidie
2002/09/14
sol0@lehigh.edu