a simple include problem / issue (errr..I think)

Hi folks, I'm looking for a really simple answer here... I've see some website have index.php display a page.... which is normal. But then I've seen the same page also have index.php?id=foo display different text with the same general layout... Now I can do stuff like www.blah.com/link.php?id=foo all i do is <? include($id. ".html"); ?> in link.php. But how do i make index.php show something, but index.php?id=foo something else?? thanks!!! /sunny __________________________________________________ Do You Yahoo!? Kick off your party with Yahoo! Invites. http://invites.yahoo.com/