use Tk;
my $number = 0;
my $mw = tkinit();
my $button = $mw->Button(-text => 'Button')->pack(-side => 'left');
my $label=$mw->Label(-textvariable=>\$number)->pack(-side=>'left');
my $timer = $mw->repeat(100, sub{
	$number = int(rand(5));
	if ( $number == 1 ){
		$button->configure(-state => 'normal');
	} else {
		$button->configure(-state => 'disabled');
	}
});
$mw->MainLoop();