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.

ASSISTANT: Sure, can I have your name to proceed further?

USER: Myself, Susan Taylor.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: Thank you for your time, sorry no reservation found on your name.

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

ASSISTANT: Thank you for opting us.