use strict;
    use warnings;
    use Tk;
    use Tk::NoteBook;
    
    # Main Entry
    my $top = MainWindow->new(); $top->title("Test");
    my $nb = $top->NoteBook()->pack(-expand => 1, -fill => 'both');
    InitializeNoteBookPage($nb->add('page1', -label => 'Page 1'), "Label for Page 1");
    InitializeNoteBookPage($nb->add('page2', -label => 'Page 2'), "Label for Page 2");
    Tk::MainLoop();
    
    # Subroutines start here
    sub InitializeNoteBookPage{
        my($nbpage, $label_description) = @_;
    
        # Widget Initialization
        my($_label_1) = $nbpage->Label( -text   => $label_description, );
        my($_entry_1) = $nbpage->Entry( -width  => 0, );    
    
        # Geometry Management
        $_label_1->grid( -in => $nbpage, -column => 1, -row => 1, -columnspan => 1, -ipadx => 0, -ipady => 0, -padx => 0, -pady => 0, -rowspan => 1, -sticky => "" );
        $_entry_1->grid( -in => $nbpage, -column => 2, -row => 1, -columnspan => 1, -ipadx => 0, -ipady => 0, -padx => 0, -pady => 0, -rowspan => 1, -sticky => "ew" );    
    
        # Resize Behavior
        $nbpage->gridRowconfigure   (1, -weight => 0, -minsize => 50,  -pad => 0);
        $nbpage->gridColumnconfigure(1, -weight => 0, -minsize => 400, -pad => 0);
        $nbpage->gridColumnconfigure(2, -weight => 0, -minsize => 400, -pad => 0);
        
        # Event callbacks
        $_entry_1->bind("<KeyRelease>", sub {
            print $nbpage->name()." ".$_entry_1->name()." KeyRelease fired\n";
        } );
            
        $nb->pageconfigure($nbpage->name(), -raisecmd => sub {
            print "\n".$nbpage->name()." raised \n";
            print "Going to fire ".$nbpage->name()." ".$_entry_1->name()."KeyRelease\n";
            $_entry_1->focus(); # If this line is commented out, no <KeyRelease> event will be fired at all ?!
            $_entry_1->eventGenerate("<KeyRelease>");
            print "Any thing happened ?\n";
        } );
    }

##</code><code>##

    page1 raised
    Going to fire page1 entryKeyRelease
    Any thing happened ?
    
    page2 raised
    Going to fire page2 entryKeyRelease
    Any thing happened ?
    
    page1 raised
    Going to fire page1 entryKeyRelease
    page2 entry KeyRelease fired
    Any thing happened ?
    
    page2 raised
    Going to fire page2 entryKeyRelease
    page1 entry KeyRelease fired
    Any thing happened ?
    
    page1 raised                        <--- using "Tab" + "LeftRight" + "Space"
    Going to fire page1 entryKeyRelease
    Any thing happened ?
    page1 entry KeyRelease fired