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

my $mw = MainWindow->new();
		$mw->geometry("300x200");
my $yyyy; 	$yyyy="" if(!$yyyy);
my $mmm;	$mmm="" if(!$mmm);
my $dd;		 $dd="" if(!$dd);

my $browseEntryyear = $mw ->BrowseEntry(
					-label => 'Select year :', -relief => 'ridge',
					-state => 'readonly', -autolistwidth => '1',
					-justify => 'right', -buttontakefocus => 1, -textvariable => \$yyyy,	-relief => 'ridge')
					-> pack( -ipadx => 15, -side => 'top', -anchor => 'e', -expand => 1);
    $browseEntryyear -> insert('end', qw(2013 2014 2015 2016 2017 2018 2019 2020));

my $browseEntrymonth = $mw ->BrowseEntry(
					-label => 'Select Month :', -state => 'readonly',
					-autolistwidth => '1', -justify => 'right', -buttontakefocus => 1,
					-textvariable => \$mmm, -relief => 'ridge')
					-> pack( -ipadx => 15, -side => 'top', -anchor => 'e', -expand => 1);
    $browseEntrymonth -> insert('end', qw(Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec));

my $browseEntryday = $mw ->BrowseEntry(
					-label => 'Select Day :', -state => 'readonly', -autolistwidth => '1',
					-justify => 'right', -buttontakefocus => 1,  -textvariable => \$dd,	-relief => 'ridge')
					-> pack(-ipadx => 15, -side => 'top', -anchor => 'e',-expand => 1);
    $browseEntryday -> insert('end', qw(01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31));

my $but = $mw -> Button(-text => " Enter ", 
					-command =>[$mw => 'destroy'], -relief => 'raised', -activebackground => "darkgreen",
					)->pack(-side => "right",-expand => 1);
my $closebutton = $mw->Button(-text => "   Quit   ",
					-command => [$mw => 'exit'], -relief => 'raised', -activebackground => "red",
					)->pack(-side => "left",-expand => 1);	

$mw->repeat(
    900,
    sub {

        if( $yyyy =~ m/\d\d\d\d/ and $mmm =~ m/[A-Z][A-z]*/ and $dd =~ m/\d\d/ ){
            $but->configure( -state => 'normal' );
        } else{
            $but->configure( -state => 'disabled' );
        }
    }
);						

	MainLoop;

	print "    selected Year   = $yyyy\n";
	print "    selected Month  = $mmm\n";
	print "    selected Day    = $dd\n";

# script continues on using varaibles above and display stdout in the main gui textframe