You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

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

ASSISTANT: Sure, may I know your good name?

USER: Thank you, my name is Sharon Williams.

ASSISTANT: Please wait for a moment.

USER: Sure, take your time.

ASSISTANT: Sorry to say that, no reservation was found with your good 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.

USER: Welcome.