PHP Update query

[Ron Piggott <ron.php@xxxxxxxxxxxxxxxxxx>]

How do I test if an UPDATE query worked

$query = "UPDATE `clients` SET `company` = '$company', `contact` =
'$contact', `phone` = '$phone', `city` = '$city' WHERE
`clients`.`reference` =$client LIMIT 1";
$client_result=mysql_query($query);

???

Ron