ESI test

Off topic, but can't find anything:

Can someone give me a quick tutorial of how to test ESI?

I figured out that I must always include headers like Surrogate-Control:
content="ESI/1.0" for squid to parse the document. I have a very simple
test page with something like this in it:

<esi:include src="www.cnn.com/index.html" onerror="continue" />

But debug always shows:

ESIIncludeStart: Starting subrequest with url 'www.cnn.com/index.html'
 starting new ESI subrequest failed

and nothing is ever sent back to the client.

-- 
Brian Akins <bakins@web.turner.com>
CNN Internet Technologies