"Rich-F" <RichF@d...> wrote in message
news:61C826B1-E1F2-4E6F-87FF-83C675E9FDF4@m......
> "Anthony Jones" wrote:
> <snip>
>
> > The point I was trying to communicate is that a browser offers the user
the
> > opportunity to override the normal operation of the local cache by using
the
> > refresh button.  This causes all requests to fulfill the page to pass
> > through local cache to the origin server regardless of whether there is
> > fresh instance of the resource in the cache.
> >
> > I'm trying to implement a similar feature for resources that have been
> > fetched with XMLHTTP.  For performance reasons I do not want to send a
> > request every time it's needed however I want to offer the user the same
> > 'refresh' option.
> <snip>
>
> Just considering this last point.....
>
> The only method that worked reliably for me was adding the
If-Modified-Since
> header and making sure that the date I used was definitely older than any
> timestamp that might be associated with the file.  (I used IE6 and
> XMLHTTP.3.0)

Ok thanks for the input.  However since changing the If-Modified-Since in
that way would always result in 200 response from the server and never a 304
it's the same is simply using the the load method on a DOM with ForceResync
enabled which is what I was hoping to avoid.