You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Nancy Hill.

ASSISTANT: How may I assist you?

USER: Due to some entrepreneurship meeting, I am going to change my existing reservation. Can you please help me in changing the reservation?

ASSISTANT: Sure, I am glad to help you.

USER: Thank you.

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

USER: No problem, thank you for the information.

ASSISTANT: Thank you for choosing us.