#!/usr/bin/perl -w
use strict;
use Tk;

my $opt = "0";
my $opt1 = "0";

my $mw = MainWindow->new();
    $mw-> geometry("400x100");
    $mw -> configure(-background => "cyan",
                    -foreground => "lightblue"
);


my ($var, $var1);

 $opt = $mw->Optionmenu(
        -background => "lightgreen",
        -options => [[jan=>1], [feb=>2], [mar=>3], [apr=>4]],
        -variable => \$var,
        -command => \&sub_opt,
       )->pack;
$opt->addOptions([may=>5],[jun=>6],[jul=>7],[aug=>8]);
my $exit_but = $mw->Button(-text=>'Exit',
    -command=>sub{
         print "Var= $var  Var1= $var1\n";
         $mw->destroy},
    -state => 'disabled',
    )->pack(-side=>"bottom");

 $opt1 = $mw->Optionmenu(
        -background => "lightgreen",
        -options => [qw(test1 test2 test3)],
        -variable => \$var1,
        -state => 'disabled',
        -command =>\&sub_opt1,
  )->pack;
     
MainLoop;

sub sub_opt {
                if($var ne " ") {
                        $opt->configure(-state => 'disabled');
                        $opt1->configure(-state => 'normal');
                } else {
                        $opt -> configure(-state => 'disabled');
                        }
}

sub sub_opt1 {
                if ( $var1 ne " ") {
                $opt1->configure(-state => 'disabled');
                $exit_but->configure(-state =>'normal');
                } else {
                        $exit_but->configure(-state => 'disabled');
                }
}