External links in PDF?

I'm missing the obvious here. I have a simple document,


@Include { doc }

//

@Document
  @InitialFont { strut Times Roman 12p }
  @InitialSpace { tex }
  @PageHeaders { Simple }

//

@Text @Begin

Here is a "http://jeffreykingston.id.au/lout/" @ExternalLink {link}.

@End @Text


then I try,

	lout example.lout -Z -o example.pdf

but no PDF viewer I try can see a hint of a link in example.pdf.

What am I doing wrong?

-- Mark