[plt-scheme] Browser caching servlet generated pages

Hi all,

I'm having a problem with web browser caching of
servlet generated pages.  My servlets generate pages
using the 

  (list "text/html"
        (blah ...))

return type.  These pages get cached by the browser. 
As the pages change frequently the cached version is
often out-of-date which causes lots of problems.  I
see this caching problem on both IE 5 and Netscape 4.7
on Win 98 (oh the shame! can I ever show my face at a
CS conference again?)  The full set of HTTP headers
returned by one of the servlets is:

  "HTTP/1.1 200 Okay\r\nDate: Mon, 03 Nov 2003
01:38:32 GMT\r\nLast-Modified: Mon, 03 Nov 2003
01:38:32 GMT\r\nServer: PLT Scheme\r\nContent-type:
text/html\r\nConnection: close\r\nContent-length:
1420\r\n\r\n"

Is there some header that I could return to prevent
caching?  Alternatively are there other techniques
people are familiar with?

Thanks,
Noel

=====
Email: noelwelsh <at> yahoo <dot> com
Jabber: noelw <at> jabber <dot> org

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