$thread_id = (isset($_GET['id']));
$thread_id = intval($_GET['id']);
$q = mysql_query("SELECT * FROM threads WHERE id = $thread_id");
Can't you use two functions on one variable?? As you can see I check if its set but it still gives me:
Notice: Undefined index: id in C:\wamp\www\bfhq\thread.php on line 7