You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I assist you today?

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

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: I am Steven Lee.

ASSISTANT: Please wait for a moment.

USER: Ok.

ASSISTANT: Sorry Lee, there is no reservation found as per your name in our database.

USER: Ok, no issues. Thank you.