Let's say I have a script like this:

<?php
$FOO = "important constant";

usefulfunction();

function usefulfunction() {
echo "The value of FOO is $FOO<p>n";
return;
}
?>

In that script, usefulfunction() won't
print the value of FOO as specified in
the main body of the script. Is there
a way to give the variable $FOO global
scope, so it could be used in functions?

I know that I could use define("FOO",
"a useful constant"), but sometimes it
would be useful to use a variable.
If there's no way to do this, I'll just
use constants.

Thanks.