# File lib/xtemplate/xpath.rb, line 167
      def untag(val, tag)
        case val
        when Hash
          newval = val.dup
          if( v = newval[tag] )
            newval[TextNode] = v
            newval.delete(tag)
          end
          newval
        when Array
          val.collect{|v| untag(v,tag)}
        else
          nil
        end
      end