Well, first of all, you have to connect to the database. <?php $db_server = "localhost"; // Usual server. :P $db_login = "USERNAME"; $db_pass = "USERPASS"; mysql_connect($db_server,$db_login,$db_pass); ?> And, its not always nesecary to have to type in $_GET['id'] to declare a GET variable. Some server software requires it, I think IIS is the only one, its what I use. And its not required for you to use the 2nd prefex for mysql_query() Just as long as you connected to the DB at the beginning of the script, all you need is mysql_query($sql).
That should clear up the error. As for you want to with the $result array, ask if needing help.