You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how best  I can assist you at this moment?

USER: I am planning to change an existing reservation, due to health issue. Can you please change my reservation?

ASSISTANT: Sure, we are here to help you. May I know your name please?

USER: My name is Rebecca Phillips.

ASSISTANT: Ok, please be on hold for some time.

USER: Sure, I will wait for your reply.

ASSISTANT: Thank you for your patience, sorry we couldn't find any reservation on your name.

USER: That's fine, thank you for your service.

ASSISTANT: Thank you for choosing us.