Nested Layout

# /app/views/layouts/application.html.erb
<!doctype html>
<html>
<head>
</head>
<body>
<%= content_for?(:content) ? yield(:content) : yield %>
</body>
</html>

# /app/views/layouts/errors.html.erb
<% content_for :content do %>
  <fieldset title="foo">
  <%= content_for?(:errors_content) ? yield(:errors_content) : yield %>
  </fieldset>
<% end %>

# /app/controllers/errors_controller.rb
class ErrorsController < ApplicationController
  def exception
      render :template => "errors/500", :status => 500 # , :layout => "errors"
  end
end