Don, First I must strongly advise that you never, ever design a Web application that depends on the back button. This is a key characteristic of a poorly designed application in most cases and is worth a second look.
Glancing at the HTTP headers you are sending, two things stand out to me. First, I am not sure that both Cache-Control headers will get sent. Even if they are, I am not sure that you're going to see consistency with Web browsers handling the multiple Cache-Control headers. Some HTTP headers are intended to be used in multiple instances, such as Set-Cookie, but Cache-Control is not one. Thus, you should specify your directives in a single Cache-Control header. In addition, many versions of Internet Explorer are known to ignore the no-store directive. This directive does not allow even the storage of a resource on your local computer. The message you see is being given by a browser that actually adheres to this directive. Only non-compliant browsers will not show this warning. Either way, however, you eliminate just about any form of caching with a compliant Web browser with all of the headers you are sending, and it sounds like you specifically want the browser to cache a previously-viewed page. So, you're going to have to make up your mind. :-) The best first step for you to take is to learn what those headers mean that you are sending. Happy hacking. Chris Don wrote: >I am having trouble with sessions. I've created a user login/password >section that uses session variables. Within this section, I have a form >where the user enters data and submits. When the user clicks on the Browser >back button, they should get back to the form with their data intact. This >is indeed what happens most of the time but some users report that they get >the following message after clicking on "Back": > >=================================== >Warning: Page has Expired The page you requested was created using >information you submitted in a form. This page is no longer available. As a >security precaution, Internet Explorer does not automatically resubmit your >information for you. > >To resubmit your information and view this Web page, click the Refresh >button. >=================================== > >When the refresh, their data is gone!!! I've gone through the docs and >placed the following headers at the top of every file. Why is this >happening and to only a few users??? > >header("Expires: Mon, 26 Jul 1997 05:00:00 GMT"); >header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT"); >header("Cache-Control: no-store, no-cache, must-revalidate"); >header("Cache-Control: post-check=0, pre-check=0", false); >header("Pragma: no-cache"); >session_cache_limiter('private_no_expire, must-revalidate'); >session_start(); > -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php