I need the Code for my Ford Focus CAR Radio and cassette player ?

I just changed the battery of my car,Ford Focus and the whole sound system that is the radio and cassette can not function. Its been displaying,"CODES". I need the code number to be able to use it again. Below is the serial number:M358181. Model number:5000 RDS EON. Part no.:98AP-18K876-BC. Thanks for your assistance.