You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Can you please help me in changing my existing reservation, as my health is not good?

ASSISTANT: Sure, may I know your name to proceed further?

USER: Thanks for the response, my name is Andrew Davis.

ASSISTANT: Please wait for a moment.

USER: Ok, sure.

ASSISTANT: We regret to inform you that there is no reservation found on your name.

USER: Ok, not an issue. Thank you for the information.

ASSISTANT: Thank you for opting us.