You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you?

USER: Owing to an emergency, my live concert in Washington got postponed. So I want you to change my existing reservation.

ASSISTANT: Sure, I am gleeful to help you. May I know your name?

USER: Sure, Donald Phillips here.

ASSISTANT: Sorry, there are no reservation found on your name.

USER: Ok, no worries at all. Thank you for your assistance.

ASSISTANT: Thank you for choosing us.