def url
      url = @path.sub(%r[^#{Regexp::quote(::Pupu.media_root)}], Regexp::quote(::Pupu.media_prefix))
      "/#{url}"
    end
def url
      url = @path.sub(%r[^#{Regexp::quote(::Pupu.media_root)}], Regexp::quote(::Pupu.media_prefix))
      "/#{url}"
    end
URL.new(root/pupu/autocompleter/javascripts/autocompleter.js)
 URL.new(Merb.root/root/pupu/autocompleter/javascripts/autocompleter.js)