From: Paul Battley <pbattley@...>
Date: 2005-04-21T09:15:49+09:00
Subject: Re: Newb CGI Question

You are reading the data, but not actually sending it to the client.

-         File.read("agent.gif")
+         print(File.read("agent.gif"))

I think that's the problem.  You can also get rid of the 304 status;
it's not appropriate:
http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html

Finally, you are sending the length of a different file in the code
sample you gave.