You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: As there is sudden change in climate at my destination, I want to change my existing reservation.

ASSISTANT: Sure, can I know your name?

USER: Nicholas Hall here.

ASSISTANT: Please hold on a moment.

USER: Ok.

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

USER: Ok, not a problem. Thank you.

ASSISTANT: Thank you for reaching us.