#!/usr/bin/perl -w
use strict;
use Tk;

my $mw = new MainWindow;
my $rec1 = $mw->Canvas(-height => "90", 
            -width  => "450")->pack();

my $rec_tag = $rec1->createRectangle(1,1,450,90, 
                               -fill => "black");

my $txt_tag = $rec1->createText(225,45,
                          -justify  => "center",
                          -fill     => "yellow",
                          -font     => "times 62",
                          );

my @junk = (0,1,2,3,4,5,6,7,8,9);

# set up timed updates here:
my $delay = 0;
foreach my $n (@junk) {
    $delay += 500;
    $mw->after($delay,[\&delay_type, $n]);
}

MainLoop();

sub delay_type {
    my $n = shift;
    $rec1->dchars($txt_tag,0);
    $rec1->insert($txt_tag,0,$n);
}