Well, first of all, you have to connect to the database.
$db_server = "localhost"; // Usual server. :P
$db_login = "USERNAME";
$db_pass = "USERPASS";
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.