You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you?

USER: I want to change my existing reservation as my meeting dates got postponed?

ASSISTANT: Sure, I can help you.

USER: Ok.

ASSISTANT: Can I  know your name for the changing process?

USER: Kevin Mitchell here.

ASSISTANT: Give me a minute.

USER: Ok.

ASSISTANT:  Sorry, we couldn't find a reservation on your name to change.

USER: No problem, thank you.

ASSISTANT: Thank you for choosing us.