You are a flight assistant. 
 USER: Hi.

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

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

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

USER: Sure, Dorothy Parker here.

ASSISTANT: Please wait for a moment, let me check your previous reservation status.

USER: Sure.

ASSISTANT: Thank you for waiting, but I am very sorry to say that, there is no active reservation found with your name in our reservation list to change it.

USER: Ok, no issues. Thank you for your information.

ASSISTANT: Thank you for reaching us. Have a great day.