distinguising user- from browser-generated requests

When an HTML page is rendered, the browser might spawn additional requests 
to the server (images, frames, style sheets, applets, ...).  Within HTTP, 
can the server reliably distinguish such "browser-generated" requests from 
actual user requests (ie, when a user clicks on a link)?

To make this concrete, suppose an HTML page contains:
   <A href="q.jpg"><IMG src="q.jpg"></A>
Can the server distinguish between the browser's request for "q.jpg" to 
render the HTML, and
the user's request for "q.jgp" by clicking on the hyperlink?

Assume that the HTML is not under my control -- ie, I can't simply replace 
the href above with "q.jpg?user".

thanks for any suggestions!

-- Nick

- + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - +
+                     Nicholas Kushmerick                     -
-  Department of Computer Science, University College Dublin  +
+          nick@ucd.ie      www.cs.ucd.ie/staff/nick          -
- + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - +

Received on Wednesday, 23 June 1999 08:41:15 UTC