You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: I want to change my existing reservation, due to some health issue. Can you please help me out?

ASSISTANT: May I know your name please?

USER: My name is George Robinson.

ASSISTANT: George Robinson sorry, no reservation found in our database.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for choosing us.