You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

USER: I am planning to change an existing reservation, due to health issue.

ASSISTANT: Ok, I am here to help you with that.

USER: Thank you.

ASSISTANT: May I know your good name?

USER: My name is Jennifer Turner.

ASSISTANT: OK, wait for a minute.

USER: Sure.

ASSISTANT: Sorry to say that, there is no reservation found on your name in our database.

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

ASSISTANT: Thank you for reaching us.