You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: My plans to visit Detroit has been postponed to other day, could you please help me in changing my existing reservation.

ASSISTANT: Sure, can I know your name please?

USER: My name is Stephen King.

ASSISTANT: Let me check King.

USER: Sure, take your own time.

ASSISTANT: Sorry King, I found no reservation by your name.

USER: Ok, no problem.

ASSISTANT: Thank you for approaching us.

USER: Thank you for your information.

ASSISTANT: You are welcome.