Hi Bayu Susiloadhy, thanks for your answer. >> function select_price($product_id,$quantity) { > --cut-- >> return True; >> } > --cut-- in the meentime I change the code that not a boolevalue was returned by the function. $q is my querystring and $db is the selected database. I insert the following: $db->query($q); $result=mysql_db_query($db,$q); while ($row = mysql_fetch_object($result)) { $price = $row->product_price; } mysql_free_result($result); echo "\n"; echo $q; // to show the sql-statement in runtime - diagnostics echo "\n"; return $price; By executing it I get two warnings both "this is not a valid Mysql-result resort". The disliked lines are the begin of the while-loop and an the mysql_free_result($result)-command. How have I to change up the script to get the product_price related to the price_group. Regards, Ruprecht ---------------------------------- Ruprecht Helms IT-Service und Softwareentwicklung Tel/Fax.: +49[0]7621 16 99 16 Homepage: http://www.rheyn.de email: info@rheyn.de ---------------------------------- -- PHP Database Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php