Thanks, guys! I have it working now. Previously, when I tried the HTML tags surrounding the PHP code...
<html>
<head><link...></head>
<body>
<?php....?>
</body>
</html>
...there were errors. However, at the time I tried it, I had problems with my MySQL query, so the script wasn't working. I guess, I associated that with the HTML tags for some reason. I just added the HTML back on, and everything works fine now.
Thanks for your help.