You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I am Joseph Harris. I want to change my existing reservation due to postpone of my live concert. Could you please help me?

ASSISTANT: Sure, I am here to help you. Please give me a moment to check your previous reservation status.

USER: Sure.

ASSISTANT: Sorry to inform you, there is no reservation found on your name in our records.

USER: No worries, thank you for the information.

ASSISTANT: Thank you for reaching us.