You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I am Timothy Evans. I want to change an existing reservation, so please help me in changing the reservation.

ASSISTANT: Sure, I am here to here to you out. Timothy Evans, we regret to inform you that there is no reservation found on your name in our records.

USER: Not an issue. Thank you for your information.

ASSISTANT: Thank you for reaching us.