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

my $mw = MainWindow->new;
$mw->geometry("300x300");

my $var =1;
my ($major, $other);

my @options = ('one', 'two', 'three', 'four', 'five');

my $topics1=$mw->Radiobutton(-text =>'Selection 1', -value => '0',
        -variable => \$major,  -command => sub {&do_smth('1')})->pack();

my $topics2=$mw->Radiobutton(-text =>'Selection 2', -value => '1',
        -variable => \$major, -command => sub {&do_smth('2')})->pack();

my $topics3=$mw->Radiobutton(-text =>'Selection 3', -value => '3',
        -variable => \$major, -command => sub {&do_smth('3')})->pack();


my $options=$mw->Optionmenu( -options => [@options], -variable => \$other,
                -command => [sub {&do_more($major, $other);}])->pack();


MainLoop;


sub do_smth{
    my $selection = shift;
    if ($selection == 2) {
        $options->options ([@options, 'six' , 'seven']) 
    } else {
        $options->options ([@options] )
    }
    $var='more' unless ($selection == 2);
}

sub do_more{
        my ($major, $other) = @_;
        print "do this: $other while Selection was $major\n";

}