You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

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

ASSISTANT: Sure, may I know your name?

USER: My name is Angela Thomas.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name.

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

ASSISTANT: Thank you.