page expiration

thanks, you provided what to me was a vague "tip"
but in further googling I found the specific instruction pointing to
"clear temporary Internet files" and that solves it.

  > >
 > Have the user check -his- settings for buffer size and history.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: page expiration 

On Thu, 22 Apr 2004 12:08:04 -0400, "Rob C" <rchin RemoveThis @panix.com> wrote:

 >a user of a web database app I support complains about getting the
 >"This page has expired" page when paging back. So he has to
 >refresh (and process re-run)

He is almost certainly using IE - 5.x IIRC - do a Google search for
"This page has expired" and IE. If that doesn't work search for
"cache-control". If your host allows you to change the cache headers
in your page's responses you can block the IE error. It's a few years
since I looked at the details, hence this is a little vague.)

However, if refreshing causes "process re-run", you should look at
either (a) issuing a HTTP level re-direct [1] after the script has
processed to prevent the same data being submitted twice or (b) some
form of session/status management to detect duplicate submissions [2].

[1] To a separate "results page", rather than displaying the "results"
from the same script that processes the input.

[2] If users are logged in you could add a username/date/time MD5 hash
as a hidden field in the submission form.

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begin OE is broken read MS knowledgebase Q265230<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: page expiration 

You need to enable some kind of cache-control headers set to
"private". This is usually caused by like PHP and Session
support. At the top of your PHP script, put:

header("Cache-control: private");

before any HTML or white space is echoed to the form and this should
fix your problem.





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 >> Stay informed about: page expiration