#!/usr/local/bin/perl

use Tk;
use strict;

my $mw = Tk::MainWindow->new();
my $entryv;
my $msgv;
my $entry = $mw->Entry(-textvariable => \$entryv)->pack(-side => 'top',-fill => 'x');
my $msg = $mw->Message(-textvariable => \$msgv)->pack(-side => 'top',-fill => 'both');

$entry->bind('<Return>',sub {$msgv = uc($entryv)});
Tk::MainLoop();