#!/usr/bin/perl -w

use Tk;

$main = MainWindow->new();

$label = $main->Label(-text=>"Enter user name:");

$label->pack(-side=>"left");

$entry = $main->Entry();

$entry->bind("<Return>", \&handle_return );
$entry->pack(-side=>"left");
MainLoop();

sub handle_return {
    $txt = $entry->get();
    print "You entered $txt\n";
    exit;
}