       mainloop
              This  procedure  sets  up  a  top-level event loop.
              Events are processed until there are no more active
              event sources, at which time the process exits.  It
              is used to build event oriented programs using  the
              TclX  shell  in  a  style similar to that used with
              wish.   If  the  global  variable   tcl_interactive
              exists  and has a true value an interactive command
              handler is started as well.   If the  command  han-
              dler  is  terminated by an EOF, the process will be
              exited.

              This commands is not useful in wishx, as  it  auto-
              matically  enters  an event loop after processing a
              script.

              This procedure is provided by Extended Tcl.
