You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. Can you please tell me how can I aid you?

USER: I am Elizabeth Harris.

ASSISTANT: Ok, please wait.

USER: I am planning to change my reservation, can you please help me out?

ASSISTANT: Sorry, I did not find any reservation on your name to change.

USER: That's fine. Thank you for your service.

ASSISTANT: Thank you for opting our service.