#!/usr/bin/perl

use warnings;
use strict;
use Tk;

my ($no,$upper_no,$mw,$realend);
$no=0; $upper_no='';

$mw = MainWindow->new;
$mw->geometry("300x100");
$mw->title("PerlTk Test");
$mw->Label(-text => "Enter a 5 digit  number")
            ->place(-relx => 0.0,-rely => 0.05);
$mw->Entry(-takefocus => 1,
    -textvariable => \$upper_no,
    -width => 12)
    ->place(-relx => 0.50, -rely => 0.05);
$mw->Button(-text => "Click to count upto that number and display them below as you count", 
    -wraplength => 250,
    -command => \&count)
    ->place(-relx => 0.5, -anchor => "center", -rely =>0.50);
$mw->Label(-textvariable => \$no,
     -relief => 'sunken', 
    -anchor => 'center')
    ->place(-relx =>0.0, -rely => 0.80, -relwidth => 1.0, -relheight => 0.2);

MainLoop;

sub count {
if ($upper_no=~/^\d+$/ and $upper_no > 0) {
if ($no < $upper_no) {
$no++;
    } 
    }
    }