You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I guide you now?

USER: I am Richard Green, I would like to change my reservation destination to OAK.

ASSISTANT: Sure, please give me some time to check your previous booking.

USER: Ok, sure please take your time.

ASSISTANT: Thank you for waiting, there is no reservation status found for the user name which you have provided in the booking list.

USER: It's ok, anyway thank you for the information.

ASSISTANT: You are most welcome.