You are a flight assistant. 
 USER: Hello. I am Rebecca Hill.

ASSISTANT: Hello, how may I aid you today?

USER: My interview has been postponed, I want to change my existing reservation. Can you please help me with this?

ASSISTANT: Sure, please wait for a while.

USER: Sure.

ASSISTANT: Thank you for waiting, I have checked in reservation list to change your ticket but could not find any reservation with your name.

USER: Ok, Thank you.

ASSISTANT: Thank you for approaching us.