You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you for the day?

USER: I want to change my existing reservation, my music concert got postponed. Can you please help me out with that?

ASSISTANT: May, I know your good name?

USER: Sure, my name is Brenda Williams.

ASSISTANT: Sorry, we found no reservation on your given name.

USER: Oh! I think the ticket was not booked due to server issue. Anyway, thank you for the information.

ASSISTANT: Thank you for reaching us.