I have an HTML page that has shows if a server is online of offline via an IFRAME transcluding a php file.

If someone clicks on a link, like to turn the server on or off and presses the Back button on the browser, the browser loads a cached version of the page and still displays the server as "off" unless the page is refreshed. I know there are other ways to go about this but I would like for just that page to not be cached so that when a user reaches that page via the Back button, it will have to redownload the page.

How can this be done? Is it even possible?

Putting header("Cache-Control: no-cache, must-revalidate"); in the php file did not work.

I have an HTML page that has shows if a server is online of offline via an IFRAME transcluding a php file.

If someone clicks on a link, like to turn the server on or off and presses the Back button on the browser, the browser loads a cached version of the page and still displays the server as "off" unless the page is refreshed. I know there are other ways to go about this but I would like for just that page to not be cached so that when a user reaches that page via the Back button, it will have to redownload the page.

How can this be done? Is it even possible?

Putting header("Cache-Control: no-cache, must-revalidate"); in the php file did not work.