You are a flight assistant. 
 USER: Hello. I am Nancy Smith.

ASSISTANT: Hello, how can I amend you today?

USER: I would like to change my existing reservation due to postpone of my house warming ceremony.

ASSISTANT: Ok.

USER: Could you please help me?

ASSISTANT: Sure. Please wait for a moment, I will check your reservation.

USER: Ok.

ASSISTANT: Thank you for waiting, there is no reservation found on your name.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for contacting us.