You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Actually my College Annul Day is postponed, so that I want to change my existing reservation. Can you help me?

ASSISTANT: Sure, I will help you.

USER: Ok.

ASSISTANT: May I know your name please to check the reservation status?

USER: Sure, I am Ryan Moore here.

ASSISTANT: Ryan, there is no record of your reservation found in our database.

USER: Ok, no issues. Anyway's thank you for your information.

ASSISTANT: Thank you for choosing us.