You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello. What can I do for you at this moment?

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

ASSISTANT: Sure, may I know your good name please?

USER: Myself, Ronald Jackson.

ASSISTANT: There is no existing reservation found on your name in our records.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for reaching us.