You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: Due to my health issue, I would like to change my recent reservation.

ASSISTANT: Sure, can I know your name?

USER: My name is Anna Robinson.

ASSISTANT: Give me a minute, let me check the details.

USER: Ok.

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

USER: That's fine. Thank you for your information.

ASSISTANT: Welcome. Have a nice day.