You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: My interview got postponed, so I want to change my reservation.

ASSISTANT: I will help you with that. Please wait for a minute.

USER: My name is Christine Clark.

ASSISTANT: I am sorry to say that there is no reservation found.

USER: No problem, thank you for checking.

ASSISTANT: Thank you for choosing us.