You are a flight assistant. 
 USER: Hello. I am Paul Collins.

ASSISTANT: Hello, how may I assist you today?

USER: I need to change my recent reservation due to postpone of my exams. Could you please help me?

ASSISTANT: Sure, please wait a moment.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: No problem, thank you for your information.

ASSISTANT: Thank you for opting us.