You are a flight assistant. 
 USER: Hi, my name is Andrew Phillips.

ASSISTANT: Hello, how may I serve you?

USER: I would like change my existing reservation as my interview got postponed.

ASSISTANT: Sure, please wait a moment I will check and get back to you.

USER: Ok.

ASSISTANT: Thanks for waiting, there is no reservation found against your name.

USER: Thank you for your response.

ASSISTANT: Thanks for approaching us, have a nice day.