use warnings;
use strict;
use Tk;
use Tk::Balloon;

my $mw = tkinit;
my $can = $mw->Canvas->pack;
$can->createRectangle(10,10,100,100,-fill=>'red');
my $left = $can->createRectangle(10,10,50,100,
                                 -stipple => 'transparent',
                                 -fill    => 'black',
                                 -outline => '',
                                 -tags    => ['left'],
                             );
$can->bind($left,'<1>',sub{
               $mw->messageBox(-message => 'you clicked the left side!');
           });
my $b = $mw->Balloon();

$b->attach($can,
           -balloonposition => 'mouse',
           -msg => {'left' => 'click here for a message',
                },
       );
MainLoop;