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

use Tk;

my $mw = tkinit();

my $txt_var;
my $spin = $mw->Spinbox(-from => 0, -to => 100, -textvariable => \$txt_var)->pack(-side => 'left');
$spin->bind('<Return>', sub {print shift . "\n" . $txt_var});

MainLoop;