#!c:/perl/bin/perl -w
use strict;
use Tk;

my $regex = '';
my $foo = '';
my $main=MainWindow->new();

$main->Entry(
    -width              => 20,
    -textvariable       => \$regex,
    -validate           => 'focusout',
    -validatecommand    => sub{ print "Regex: $regex\n" },
)->pack();

$main->Entry(
    -width              => 20,
    -textvariable       => \$foo,
    -validate           => 'focusout',
    -validatecommand    => sub{ print "Foo:   $foo\n" },
)->pack();

MainLoop;