You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help 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: Myself Shirley Green.

ASSISTANT: I regret, there is no reservation by your name.

USER: Not a big deal, anyhow thank you very much for checking the reservation status.

ASSISTANT: Thank you.