You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am looking for changing my reservation due to health issue. Can you please help me out with that?

ASSISTANT: Sure, can I know your name?

USER: My name is Andrew Turner.

ASSISTANT: Please hold on a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on given name.

USER: Oh! I think the ticket was not booked due to server issue. Thank you for the information.

ASSISTANT: Thank you for reaching us.

USER: Welcome.