You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you at this moment?

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

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Please hold on a moment, I will check your previous reservation status.

USER: Sure.

ASSISTANT: There is no previous reservation available under your name.

USER: That's ok, no problem. Thank you for the information.

ASSISTANT: Thank you for contacting us, have a nice day.