You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: My final exam dates are postponed, can you please help me for changing the existing reservation?

ASSISTANT: Sure, on which name can I change the reservation?

USER: Sure, the reservation is on the name of Margaret Thompson.

ASSISTANT: I am sorry no reservation found on your name.

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

ASSISTANT: Thank you for choosing us.