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

my $mw = MainWindow->new();
$mw->geometry("600x600+50+50");
$mw->resizable(0, 0);

$mw->Button(-command => \&menu_file_new, -text => "Neue Seite")->pack();

# NoteBook erstellen:
my $notebook = $mw->NoteBook()->place(-x => 5, -y => 150, -width => 590, -height => 445);
my $pagecounter = 0;

MainLoop();

sub menu_file_new {
    # Create new Notebook:
    my $nr = ++$pagecounter;
    my $nbpage = $notebook->add("nb$nr", -label => "Test $nr");
    $nbpage->Label(-text => "test it $nr")->pack();
}