You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I made a reservation earlier this week to give a seminar, but my seminar has been postponed. Can you please help me in changing my reservation?

ASSISTANT: Sure, We are here to help you. May I know your name for the changing process?

USER: Myself Rachel Mitchell.

ASSISTANT: Please wait a while.

USER: Ok.

ASSISTANT:  Thank you for waiting, but I am sorry to say that, there is no active reservation found with your name in our database to change it.

USER: It's ok, thank you so much.

ASSISTANT: Thank you for reaching us.