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

use Tk ();
use Tk::Dialog ();

my $mw = MainWindow->new();
my $frame = $mw->Frame()->pack();

use vars qw($Grey $Red);
$Grey = '#aaaaaa';
$Red  = '#ff0000';

my @fields = ();
for my $j (1..20) {
    my @row = ();
    for my $i (1..10) {
    push (@row, $frame->Label(-text => '   ', -background => $Grey,
               
       -border => 1, -relief => 'sunken'));
    } # for
    push (@fields, \@row);
    my ($first, @other) = @row;
    $first->grid(@other);
} # for j

&SetColor(\@fields, 4,2, $Red);
for my $j (1..3) {
    &SetColor(\@fields, 3,$j, $Red);
} # for

$mw->after('2000', sub {
    for my $j (1..3) {
    &SetColor(\@fields, 3,$j, $Grey);
    &SetColor(\@fields, 4,$j, $Red);
    } # for
    &SetColor(\@fields, 5,2, $Red);
});

&Tk::MainLoop;
# ------------------------------------------------------------
sub SetColor {
    my ($fields, $i, $j, $color) = @_;

    $fields->[$i]->[$j]->configure(-background => $color);
} # SetColor