You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: Can you help me in changing my recent reservation, as my exam is postponed?

ASSISTANT: Sure, I will help you in booking. May I know your name to proceed further?

USER: I am Michelle Lee.

ASSISTANT: Michelle Lee, regret to inform that there is no active reservation found under your name to proceed.

USER: That's ok, thank you.

ASSISTANT: Thank you for reaching us.