Google Analytics Rails helper

gistfile1.rb

#   <%= google_analytics 'UA-XXXXXX-XX' %>
# </body>

# application_helper.rb

def google_analytics(id = nil)
  content_tag(:script, :type => 'text/javascript') do
    "var _gaq = _gaq || [];
    _gaq.push(['_setAccount', '#{id}']);
    _gaq.push(['_trackPageview']);
    (function() {
      var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
      ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
      var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
    })()"
  end if !id.blank? && Rails.env.production?
end