You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Due to change in the venue, I would like to change my existing reservation.

ASSISTANT: Sure, please wait for a moment. May I know your good name please?

USER: My name is Scott Nelson.

ASSISTANT: Sorry, there is no previous reservation found on your name to change.

USER: That's fine.

ASSISTANT: Thank you for contacting us.

USER: Thank you for the information.