Also, instead of the tedious deleting and refilling the listboxes, I use the -listvariable option to show an array. Now, all you need to do is empty and refill the arrays, and the listbox will take care of itself.

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

my $mw = tkinit;

my $topframe = $mw->Frame()->pack(-fill=>'x' );
my $mainframe = $mw->Frame()->pack(-expand=>1, -fill=>'both' );

my $exit_b = $topframe->Button(-text=>'Exit',
            -command=> sub{ exit } )->pack(-side => 'right', -padx=>20
+);

my @array1=();
my $l1 = $mainframe->Scrolled('Listbox',
              -listvariable => \@array1,
              -scrollbars => 'ose')
              ->pack( -side => 'left', -expand=>1, -fill=>'both' );

my @array2=();
my $l2 = $mainframe->Scrolled('Listbox',
              -listvariable => \@array2,
              -scrollbars => 'ose')
              ->pack( -side => 'left', -expand=>1, -fill=>'both' );

my @array3=();
my $l3 = $mainframe->Scrolled('Listbox',
              -listvariable => \@array3,
              -scrollbars => 'ose')
              ->pack( -side => 'left', -expand=>1, -fill=>'both' );

&update;

my $repeater =  $mw->repeat(5000,\&update);

MainLoop;

sub update {

   foreach my $arr_ref (\@array1,\@array2,\@array3){
         
              @$arr_ref = ();
              for (1..100){
               push @$arr_ref, rand 10000;
               #sort @$arr_ref;  #do a text sort on filenames
               $mw->update;
              }
    }

}
[download]

Thank you for all the help I really appreciate the gesture of doing a small program :o) and it really make more sense that the book This is how I want it

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

use Tk;
use Tk::BrowseEntry;

use Cwd;
use List::Util qw(shuffle);


my $mw = MainWindow->new(
    -relief => 'raised',
    -bd => 2,
);

$mw->title("Asociacion de Agentes Aduanales de Matamoros --- Validacio
+n Automatica");
$mw->geometry("1024x764");
my $topframe = $mw->Frame()->pack(-fill=>'x' );
my $mainframe = $mw->Frame()->pack(-expand=>1, -fill=>'both' );
my $exit_b = $topframe->Button(-text=>'Exit',
            -command=> sub{ exit } )->pack(-side => 'right', -padx=>20
+);
my $text1 = $topframe->Label(-text => "Archivos Por enviar")->pack(-si
+de => 'left',
                                                 -expand => 1);
my $text2 = $topframe->Label(-text => "Archivos Por Enviados")->pack(-
+side => 'left',
                                                 -expand => 1);
my $text3 = $topframe->Label(-text => "Archivos de Respuesta")->pack(-
+side => 'left',
                                                 -expand => 1);
my $box1 =   Build_Listbox_One($mw);
my $box2 =   Build_Listbox_Two($mw);
my $box3 =   Build_Listbox_Three($mw);
my ($enviar, $enviados, $respuestas) = Start_Directory_Monitors( $mw, 
+$box1, $box2, $box3 );

Tk::MainLoop();


sub Build_Listbox_One {

my $box1 = $mainframe->Scrolled('Listbox',
              -scrollbars => 'ose')
              ->pack( -side => 'left', -expand=>1, -fill=>'both' );

return $box1;
}


sub Build_Listbox_Two {

my $box2 = $mainframe->Scrolled('Listbox',
              -scrollbars => 'ose')
              ->pack( -side => 'left', -expand=>1, -fill=>'both' );

return $box2;
}


sub Build_Listbox_Three {

my $box3 = $mainframe->Scrolled('Listbox',
              -scrollbars => 'ose')
              ->pack( -side => 'left', -expand=>1, -fill=>'both' );

return $box3;
}


sub Start_Directory_Monitors {
    my $mw = shift;
    my $enviar_display    = shift;    
    my $enviados_display  = shift;
    my $respuesta_display = shift;
    my $enviar = $mw->repeat(5000, [ \&list_dir_enviar,     $enviar_di
+splay    ] );
    my $env    = $mw->repeat(5000, [ \&list_dir_enviados,  $enviados_d
+isplay  ] );
    my $res    = $mw->repeat(5000, [ \&list_dir_respuesta, $respuesta_
+display ] );

    return  $enviar, $env, $res;
}

# monitor enviados
sub list_dir_enviar {
    my $box = shift;

    $box->delete(0,'end'); # empty listbox

    my @items = glob "c:/AAAvalida/valida/enviar/*.*";
    foreach (@items) {
        $box->insert('end', $_);
    }

}


sub list_dir_enviados {
    my $box1 = shift;

    $box1->delete(0,'end'); # empty listbox

    my @items = glob "c:/AAAvalida/valida/enviados/*.*";
    foreach (@items) {
        $box1->insert('end', $_);
    }

}

sub list_dir_respuesta {
    my $box2 = shift;

    $box2->delete(0,'end'); # empty listbox

    my @items = glob "c:/AAAvalida/valida/respuestas/*.*";
    foreach (@items) {
        $box2->insert('end', $_);
    }

}
[download]

Thank you