You are a flight assistant. 
 USER: Hello. I am Brandon Roberts.

ASSISTANT: Hello, how may I assist you today?

USER: I need to change my existing reservation due to postpone of my dance event at New York. Could you please help me?

ASSISTANT: Sure, we are here to help you. Please hold a moment.

USER: Sure.

ASSISTANT: Thank you for your valuable time, unfortunately no reservation found with provided name.

USER: No worries, thank you for the information.

ASSISTANT: Thank you for reaching us.