note 28468 rejected from function.setcookie by tix

I'm creating an e-commerce website, and I just need clarification as to whether a MySQL query is considered as "browser output". I ask because I have the following code, but the cookie isn't being set: if (mysql_num_rows(mysql_query("select * from $cart->user_table where username=\"$username\" and userpass=\"$userpass\"", $cart->dblink)) != 1) { $errormsg = "Invalid username or password. Please try again."; } else { setcookie("jackloren_user", "$username:$userpass", time() + 2592000); // expires in 30 days } The cookie is able to be set before the query, but not after. Is a MySQL query considered as that dreaded browser output that messes up cookie creation? And if so, why? And finally, has anyone found a way around this problem without hindering the functionality of the script? Thanks. Dogga