You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you for the day?

USER: I need to change my existing reservation as my exams got postponed, can you please help me with that?

ASSISTANT: Sure, I am gleeful to help you with that. May I know your name please?

USER: Shirley Taylor here.

ASSISTANT: Please wait for a while, let me check your previous reservation status.

USER: Sure.

ASSISTANT: Thank you for waiting.

USER: Ok.

ASSISTANT: There is no reservation found under your name in our database to change.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you for contacting us, have a great day.