You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

USER: Myself Kevin Thomas, and I want to change my existing reservation.

ASSISTANT: Sure, please wait for a minute.

USER: OK.

ASSISTANT: Sorry Kevin, no reservation found on your name.

USER: OK, that's fine.

ASSISTANT: Thank you for choosing us.

USER: Thank you, for your kind information.