You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello. How may I aid you?

USER: Can you please help me in changing my existing reservation, as my exam got postponed.

ASSISTANT: May I know your name?

USER: Myself, Jonathan Lee.

ASSISTANT: Sorry, no reservation found on your name.

USER: Ok, no issues, thank you for your information.

ASSISTANT: Thank you.