sub WriteToScreen {
      my ($msg) = @_;

      $screen->insert("1.0", $msg);
      $numlines = ($screen->index("end")-1);
      $screen->configure(-state => "normal");
      if ($screen->index("end-1c") != "1.0") {
         $screen->insert_end("\n");
      }
      $screen->insert_end($msg);
      $screen->see("1.0");
      $screen->configure(-state => "disabled");
      $screen->yview("end");
}