Your host company is at least somewhat intelligent - register_globals presents security risks.
Anyway, here's an example of code using register_globals:
<?php
echo "You just posted your name, " . $name . "!";
// versus
echo "You just posted your name, " . $_POST['name'] . "!";
?>
Also note that I used the full "<?php" tag versus the short tag "<?". You might want to make this change in your scripts as well - short tags, like register_globals, are deprecated.
For more information on $POST, $COOKIE, $SESSION, $GET, etc., see this man page: [man]variables.predefined[/man].
EDIT: Blah... bpat beat me to it. I type too slowly 🙁