Popup window in Rails 3.1


I need to open a popup window with a form and submit button, while the
background will be gray and disabled the parent window.
I found the Facebox and the FaceboxRender solutions, but they didn’t
work for me.
I get a routing Error: uninitialized constant
I also found a pure java script solutions, but I prefer a solution in
rails 3.1 (with or without java script).

I use rails 3.1, ruby 1.9.2 and jquery 1.6.1

Can anyone help me? Please!