Subquery

hi, can some one enlighten me on what is wrong with my query? I want to set the fax number of all the employees of a particular company to the company's fax number. This is because the employees do not have personal fax machines, thus instead of just leaving T020FaxNo blank, I want to update it with the company's fax number. However, the following doesn't work?! i'm hoping i don't have to write a PHP while loop to do this simple task! =( UPDATE T020Employee SET T020FaxNo = ( SELECT T010FaxNo FROM T010Company WHERE T010CoCd = 'XXX' ) WHERE T020CoCd = 'XXX' MySQL version: 3.23.58. PHP version: 4.3.4. My database structure is: T010Company =========== T010CoCd (primary key) T010CoName T010Address T010TelNo T010FaxNo T020Employee =========== T020CoCd (primary key, linking to T010CoCd) T020EmpCd (primary key) T020JobTitle T020TelNo T020FaxNo Thanks so much! Hwee