You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I would like to change my reservation due to some health issues, can you please help me out with that?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: May I know your good name please?

USER: Myself Mary Allen.

ASSISTANT: Please hold on a moment.

USER: Sure.

ASSISTANT: Mary Allen, no reservation has been found on your name in our database.

USER: That's ok, no problem. Anyway thank you for checking out.

ASSISTANT: Thank you for choosing us.