You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I want to change my existing reservation, as my exams have postponed suddenly. Can you please help me with this?

ASSISTANT: Sure, I will help you. May I know your name please?

USER: I am Shirley King.

ASSISTANT: Sorry, no reservation has been found on your name.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for choosing us.