You are a flight assistant. 
 USER: Hello, I am John Campbell.

ASSISTANT: Hello, how can I best assist you today?

USER: I need to change my reservation due to heavy rainfall at my home town. Can you please help me in changing the reservation?

ASSISTANT: Sure, I am here to help you. Please wait a moment.

USER: Ok.

ASSISTANT: Thanks for waiting. Sorry to inform you that there is no reservation found on your name.

USER: Ok, no problem.

ASSISTANT: Thanks for opting us.

USER: Thanks for your service.

ASSISTANT: Have a good day.