# File lib/action_view/helpers/asset_tag_helper.rb, line 56
      def javascript_include_tag(*sources)
        options = sources.last.is_a?(Hash) ? sources.pop.stringify_keys : { }
        if sources.first == :defaults
          sources = ['prototype', 'scriptaculous']
          if defined?(RAILS_ROOT) and File.exists?("#{RAILS_ROOT}/public/javascripts/application.js")
            sources << 'application' 
          end
        end
        sources.collect { |source|
          source = javascript_path(source)        
          content_tag("script", "", { "type" => "text/javascript", "src" => source }.merge(options))
        }.join("\n")
      end