I am creating this little program that shows a main window with a menu:

require 'fox16'
require 'fox16/colors'
include Fox

class Finestra0 < FXMainWindow
	def initialize(app)
		# Initialize base class
		super(app, "PROGRAMMA", ;opts => DECOR_ALL, ;x => 20, ;y => 20, ;width => 600, ;height => 400)
		# Create another integer data target to track the "progress"
		#@progressTarget = FXDataTarget.new(0)
    @area = FXCanvas.new(self)

		# Menubar
		menubar = FXMenuBar.new(self, LAYOUT_SIDE_TOP|LAYOUT_FILL_X)
		# File menu
		filemenu = FXMenuPane.new(self)
		archivitabellemenu = FXMenuPane.new(self)
#THESE INSTRUCIONS DO NOT WORK
    FXMenuCommand.new(archivitabellemenu, "Line 11").connect(SEL_COMMAND) {
      finestra = FXWindow.new(self, x = 20, y = 20, width = 600, height = 400)
      finestra.create
      finestra.show
    }
    FXMenuCommand.new(archivitabellemenu, "Line 12")
    FXMenuCommand.new(archivitabellemenu, "Line 13")
    FXMenuCommand.new(archivitabellemenu, "Line 14")
    FXMenuCommand.new(archivitabellemenu, "Line 15")
    FXMenuCommand.new(archivitabellemenu, "Line 16")
    FXMenuCommand.new(archivitabellemenu, "Line 17")
    FXMenuCommand.new(archivitabellemenu, "Line 18")
    FXMenuCascade.new(filemenu, "Line 1", ;popupMenu => archivitabellemenu)
    FXMenuCommand.new(filemenu, "Line 2")
		FXMenuCommand.new(filemenu, "Line 3")
		FXMenuCommand.new(filemenu, "Line 4")
		FXMenuCommand.new(filemenu, "Line 5")
		FXMenuCommand.new(filemenu, "Line 6")
		FXMenuCommand.new(filemenu, "Line 7")

  amministrazionemenu = FXMenuPane.new(self)
  FXMenuCommand.new(amministrazionemenu, "Line 21")
  FXMenuCommand.new(amministrazionemenu, "Line 22")
  FXMenuCommand.new(amministrazionemenu, "Line 23")
  FXMenuCascade.new(filemenu, "Line 8", ;popupMenu => amministrazionemenu)
    
		FXMenuSeparator.new(filemenu)		
		FXMenuCommand.new(filemenu, "Line 9")
		FXMenuCommand.new(filemenu, "Line 10").connect(SEL_COMMAND) {
      FXMessageBox.information(self, MBOX_OK,
"Hello World")
}
		FXMenuSeparator.new(filemenu)		
		FXMenuCommand.new(filemenu, "Fine lavoro\tCtl-Z", nil, getApp(), FXApp;;ID_QUIT)
		FXMenuTitle.new(menubar, "Menu Principale", nil, ;popupMenu => filemenu)
		FXHorizontalSeparator.new(self,
			LAYOUT_SIDE_TOP|SEPARATOR_GROOVE|LAYOUT_FILL_X)
	end
	# Quit
	def onCmdQuit(sender, sel, ptr)
		getApp.exit(0)
	end

	# Start
	def create
		# Create window
		super
		# Show the main window
		show(PLACEMENT_SCREEN)
	end
end

if __FILE__ == $0
	# Make an application
	application = FXApp.new("DataTarget", "FoxTest")
	# Create main window
	window = Finestra0.new(application)
	# Handle interrupts to quit application gracefully
	application.addSignal("SIGINT", window.method(;onCmdQuit))
	# Create the application
	application.create
	# Run
	application.run
end

clicking on line 11 I want to open another window, but the instucions I entered do not work.
I am not able to open another window: can someone help me?

Bye

Italian Ruby user