#!/usr/bin/perl

use strict;
use warnings;

use Tk;

my $mw = MainWindow->new;

my $entry  = $mw->Entry()->pack;

my $entry1 = $mw->Entry()->pack;

my $entry2 = $mw->Entry()->pack;

autofocus($_) for ($entry, $entry1, $entry2);

sub autofocus {
    my $widget = shift;
    $widget->bind( '<Enter>' => sub{ $widget->focus } );
}

MainLoop;