You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello. How can I aid you today?

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

ASSISTANT: Sure, I am here to help you with that, can I know your good name to proceed further?

USER: Myself, John Green.

ASSISTANT: Thank you. Please be online for a while. I will check your reservation status and get back to you.

USER: Ok.

ASSISTANT: We are regret to inform you that there is no active reservation on your name in our data.

USER: Ok, no issues. Thank you for checking.

ASSISTANT: Thank you for reaching us.