You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I guide you for today?

USER: Owing to an emergency, my meeting with client got postponed, so I want you to change my existing reservation.

ASSISTANT: I will help you with that. May I know your name?

USER: Sure, Katherine Williams here.

ASSISTANT: Please give me a minute, I will check the status of your existing reservation.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found under your name in our database.

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

ASSISTANT: Thank you for contacting us, have a nice day.