===========
use Tk;
use strict;

my $mw = MainWindow->new;
   my  $button1= $mw-> Button(-text=>"newWin", 
         -command=> 
   sub {
        my $top2 = $mw -> Toplevel(); 
        my $label1= $top2-> Label(-text=>'hi here')->pack(); 
    }
)->pack;


MainLoop;
================