You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, What can I do for you today?

USER: Due to a sudden meeting at office with my client on my boarding day, I want to change my recent reservation.

ASSISTANT: Sure, I will help you. Please provide your good name.

USER: Sure, my name is Helen Allen.

ASSISTANT: Ok, please wait for a couple of minutes.

USER: Sure.

ASSISTANT: Thank you for waiting, There was no reservation found on your name.

USER: That's Ok, thanks for your help.

ASSISTANT: Thank you for picking us.