how can I make my webpage get the newest page?

Hello,
how can I Set an expiry for your pages to be cache'd and then updated after that date?
and set when the page was last updated which is then checked against another value to see if the new page shoud be retreived from the server?
thanks.

You don't, your browser decides if it needs to. If you want, you can send cache headers with the header() (http://www.php.net/function.header) function.

but not always the browser is updating when it needs to.