You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I already have a reservation to have a trip with my friends. Due to shortage of holidays trip has been postponed. Can you please change my existing reservation?

ASSISTANT: Sure, may I know your good name?

USER: My name is Brian Hill.

ASSISTANT: Please wait for a minute.

USER: Sure.

ASSISTANT: Sorry to inform that there is no reservation found with your name.

USER: No problem. Thanks for helping me.

ASSISTANT: Thank you for availing us.