# File lib/action_view/helpers/active_record_helper.rb, line 120
      def error_messages_for(*params)
        options = params.last.is_a?(Hash) ? params.pop.symbolize_keys : {}
        objects = params.collect {|object_name| instance_variable_get("@#{object_name}") }.compact
        count   = objects.inject(0) {|sum, object| sum + object.errors.count }
        unless count.zero?
          html = {}
          [:id, :class].each do |key|
            if options.include?(key)
              value = options[key]
              html[key] = value unless value.blank?
            else
              html[key] = 'errorExplanation'
            end
          end
          header_message = "#{pluralize(count, 'error')} prohibited this #{(options[:object_name] || params.first).to_s.gsub('_', ' ')} from being saved"
          error_messages = objects.map {|object| object.errors.full_messages.map {|msg| content_tag(:li, msg) } }
          content_tag(:div,
            content_tag(options[:header_tag] || :h2, header_message) <<
              content_tag(:p, 'There were problems with the following fields:') <<
              content_tag(:ul, error_messages),
            html
          )
        else
          ''
        end
      end