use strict;
use Tk;
use Tk::NoteBook;

my $mw = MainWindow->new;
$mw->geometry('100x200');
my $nb = $mw->NoteBook()->pack(-fill => 'both', 
                               -expand => 1);
								
my $page_tab_01=$nb->add ("TAB-1", 
                          -label=>'TAB-1', 
                          -raisecmd=>\&callback_01);

my $page_tab_02=$nb->add ("TAB-2", 
                          -label=>'TAB-2', 
                          -raisecmd=>\&callback_02);

my $t_button = $page_tab_01->Button(-text=>'OK', 
                                   -command=>sub{exit});

MainLoop;

sub callback_01 {
    $t_button->packForget;
    $t_button->pack(-in=>$page_tab_01);
}

sub callback_02 {
    $t_button->packForget;
    $t_button->pack(-in=>$page_tab_02);  #<---ERROR HERE
}