#!/usr/bin/perl
use warnings;
use Tk;
use strict;

my $w=20;
my $x=0;
my $y=0;

my $mw=tkinit;

my $f1 = $mw->Frame()->pack();
my $f2 = $mw->Frame()->pack();

my $c1 = $mw->Canvas->pack(-in =>$f1);
my $c2 = $mw->Canvas(-bg=>'black')->pack(-in =>$f2);

my $b = $mw->Button(-text=>'Switch Frames',
                    -command => sub{
	            $c1->packForget; 	    
		    $c2->packForget;
	
		    $c1->pack(-in => $f2);
	            $c2->pack(-in => $f1);
		    
		    })->pack;


for (0..9) {
 my $item=$c1->createRectangle($x,$y,$x+20,$y+20,
   -fill=>'red',
     -activefill=>'yellow');
      $x+=20;
      }

      
MainLoop;