You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I  help you?

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

ASSISTANT: Just a moment please.

USER: Sure.

ASSISTANT: May I know your name please?

USER: Yes, I am Jennifer Edwards.

ASSISTANT: I am sorry no reservation found on your name.

USER: Ok, not an problem. Thank you for your help.

ASSISTANT: Thank you for choosing us.