    # File temp/element.rb, line 222
        def namespace(prefix=nil)
          if prefix.nil?
            prefix = prefix()
          end
          if prefix == ''
            prefix = "xmlns"
          else
            prefix = "xmlns:#{prefix}" unless prefix[0,5] == 'xmlns'
          end
          ns = attributes[ prefix ]
          ns = parent.namespace(prefix) if ns.nil? and parent
          ns = '' if ns.nil? and prefix == 'xmlns'
          return ns
        end