Thank you both very much.
Ken, I was not aware of those ready-made functions.
I think the easiest thing to do is to to the server-side include (I'm already doing it with thermometer.php on my home page). The problem I'm having with that is that I only want the php to display if there is an advisory. Otherwise, I'd like something else (non-php) to display in that area as it does now. Is there a way to test for the advisory before doing the include? I'm thinking that the easy way would be to parse the value of the advisory file unless someone knows a way to do this with php.