#!/usr/local/bin/perl

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

my $mw = MainWindow->new();
$mw->title('Simple example');

my $status  = $mw->Label(
                  -width => 20,
                  -relief => 'groove',
              )->pack();

my $balloon = $mw->Balloon(-statusbar => $status);

my $menu    = $mw->Optionmenu(
                  -textvariable => \my $res,
                  -options      => [qw(A B C D)],
              )->pack();

$balloon->attach(
    $menu,
    -msg => [qw(a b c d)],

    #-msg => 'foo',
    # this works, but you get the same msg for all menu entries, of course
);

MainLoop;