#!/usr/bin/perl 

use strict;
use warnings;
use SystemTray::Applet::Gnome;

my $num = 10;
my $applet = SystemTray::Applet::Gnome->new( 
    "text" => $num,
    "callback" => sub { 
        my ($self) = @_; 
        $self->{"text"} = $num;
    }
);