def type
        case attributes['type']
          when 'cancel' then :cancel
          when 'form' then :form
          when 'result' then :result
          when 'submit' then :submit
          else nil
        end
      end
 
      ##
      # Set the type (see type)
      def type=(t)
        case t
          when :cancel then attributes['type'] = 'cancel'
          when :form then attributes['type'] = 'form'
          when :result then attributes['type'] = 'result'
          when :submit then attributes['type'] = 'submit'
          else attributes['type'] = nil
        end
      end