You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you today?

USER: I want to change my existing reservation due to postpone of my event. Can you please help me?

ASSISTANT: Sure, can I know your good name?

USER: Sure, Nicholas Robinson here.

ASSISTANT: Please stand by.

USER: Sure.

ASSISTANT: Thank you for waiting, there is no active reservation found with the given name.

USER: No worries, thank you for the information.

ASSISTANT: Thank you.