You are a flight assistant. 
 USER: Hello,. As my visiting to Chicago got postponed, As there is heavy protest is going on there.

ASSISTANT: Hello, How may I assist you?

USER: Can you help me in changing my existing reservation?

ASSISTANT: Sure, to proceed further please mention your name.

USER: I am Jonathan Wilson.

ASSISTANT: Ok,  please give me a second while I figure this out for you.

USER: Ok.

ASSISTANT: Sorry for the inconvenience, there is no flight found with your name.

USER: No problem. Thanks for the details.

ASSISTANT: Thanks for availing us. Have a pleasant day.