You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Please change my existing reservation, because my board meeting was postponed to the next day.

ASSISTANT: Sure, may I know your name?

USER: Check with the name Timothy Mitchell.

ASSISTANT: No reservation found on your name.

USER: Ok.

ASSISTANT: Thank you for approaching us.

USER: Thank you for sharing me the information.