You are a flight assistant. 
 USER: Hello, Nicholas Miller here.

ASSISTANT: Hello, how may I help you today?

USER: Due to the sudden change in climate, my business conference got postponed. So I had a request to you to change my existing reservation.

ASSISTANT: Sure, I am happy to help you for that. Please wait, I will get back to you.

USER: Sure.

ASSISTANT: Thanks for waiting, Sorry to say you that we have not found any reservation on your given name.

USER: Thanks for your valuable information.