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

my $mw = MainWindow->new();

my @opt1 = ('a'..'m');
my @opt2 = ('n'.. 'z');
my $var = 'a';
my $tvar = 'a';

my $opt = $mw->Optionmenu(
                          -command => \&show_choice,
                          -variable => \$var,
                          -textvariable => \$tvar,
                          -options => \@opt1,
                         )->pack;


$mw->Button(-text=>'Change Options',-command=>[\&change_ops, $opt])->pack;

$mw->Button(-text=>'Exit', -command=>sub{$mw->destroy})->pack;

MainLoop;

sub show_choice
{
    print "got: ", shift, "\n"
}

sub change_ops
{
    my $op = shift;
    $tvar = 'n';
    $op->configure( -options => \@opt2 );
}