What you want can be achieved using Tk::after and the -textvariable option (see Tk::options) most widgets support (like buttons, lables, ...). Here is an example:

#!/usr/bin/perl -w
use strict;
use Tk 8;
use vars qw/ $VARIABBBBBBB $TIMER /;

my $MWin = new Tk::MainWindow(-background=>'green',
                              -width=>400,
                              -height=>400
                             ,);


$MWin->Label(-textvariable => \$VARIABBBBBBB,
                  -relief => 'flat',
                  ,)->pack();


    $MWin->Button(-text => "BUTT On",
                                   -relief => 'groove',
                                   -borderwidth => 2,
                                   -padx => 3,
                                   -pady => 3,
                                   -command => \&ffffffff,
                                  ,)->pack();

&MainLoop();


sub ffffffff
{
    $TIMER->cancel() if $TIMER;
    $VARIABBBBBBB = 0;
    $TIMER = $MWin->repeat(100, sub { $VARIABBBBBBB++});
}
[download]

Also, I am reccomending to everybody to go and read How to RTFM, it's a lifesaver.

 

______crazyinsomniac_____________________________ Of all the things I've lost, I miss my mind the most. perl -e "$q=$_;map({chr unpack qq;H*;,$_}split(q;;,q*H*));print;$q/$q;"