failed query results

Hello all, i am trying to query a mysql database to see if a customer all ready exists in a database and if so then use there customer id to insert data into another table. Can anyone tell me what valuse mysql returns if the query returns no value? i have the following code: $customer_id_check=("SELECT id FROM $customer_table WHERE firstname = '$firstname' && lastname = '$lastname' && email = '$email'"); $result1=mysql_query($customer_id_check); if (!$result1) { print "theres no such customer!"; } which i thought should echo 'theres no such customer!' if a customer didnt exist who fitted the query, however it doesnt and if i echo $result1 i get 'Resource id #2 not what i was expecting (was more expecting something along the lines of NULL). Thanks for any help in advance!!! Cheers From baldey_uk