Static load a window with SimpleApp problem!!

[eacevedo78]

Hi, I'm trying to show a window component by default when de UI is loaded, the code is:

class HelloWorld < Netzke::Basepack::SimpleApp

  component :ventana do |f|

    f.klass= Netzke::Basepack::Window

    f.width=400

    f.height=300

    f.html="Welcome to the system. If you are an user...."

  end

    

  js_configure do |c|

    c.mixin # mix in methods from hello_world/javascripts/hello_world.js

  end

  

  def main_panel_config

    super.merge({html: "Main Panel",items: [:ventana]})

  end

end

In chrome I get this error: Uncaught TypeError: Cannot read property 'dom' of null

Somebody knows how can I solve this?

Thank's