[racket] Scribble: Different output for LaTeX and HTML backends

Hi All,

I have a YouTube video, that I'd like to embed in the HTML output using the
following code:

<iframe title="YouTube video player" class="youtube-player"
type="text/html" width="480" height="390"
src="http://www.youtube.com/embed/J3WIPS3Uh_A?rel=0"
frameborder="0"></iframe>

In the PDF version, I'd like to use:

@hyperlink["http://www.youtube.com/watch?v=J3WIPS3Uh_A"]{Proof for the
cosine relation in an acute trinagle}

How can I detect whether pdf or html is being generated?
Is there a parameter I can use?

--
Jens Axel Søgaard