You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: Due to heavy rains I want to change my reservation, can you help me out?

ASSISTANT: Sure, can I know your name?

USER: My name is James Clark.

ASSISTANT: I'm sorry James, there are no reservations with your name.

USER: Ok, thank you for checking.

ASSISTANT: Thank you, have a good day.