You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: Owing to an emergency, my business conference got postponed, so I want you to change my existing reservation.

ASSISTANT: Sure, I can help you. May I know your name?

USER: Sure, Kevin Walker here.

ASSISTANT: Thank you. Please wait for a while, let me check your reservation status in our database.

USER: Sure.

ASSISTANT: Sorry, I did not find any reservation under your name in our database.

USER: Ok, no worries at all. Thank you.

ASSISTANT: You are most welcome.