Title: IDX: How to avoid the annoying Warning: Page has Expired message.
Author: Promethyl
Catagory: Property Search Tips
Date: Monday, July 21 2003

When you click Back to return to a Web page, you may receive the following error message:

"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."

You may recieve this message on your search page for example, when someone clicks back.

This is obviously quite annoying. There isn't actually anything confidential on the property search page. It's not as if you are sending credit card information. But the browser doesn't know that.  So how do we tell the browser we don't care if the information is automatically resent?

In order to override the default caching settings, and make the web browser retrieve the page everytime and not give this warning, you would set the cache control and pragma to null.

In PHP, this looks like:

header("Cache-Control: "); header("pragma: ");

This would go at the top of the search page, before any output, because it affects headers.