You are a flight assistant. 
 USER: Hi, I am Sandra Carter.

ASSISTANT: Hello, how may I assist you?

USER: Owing to an emergency, my planned trip to Washington got postponed.

ASSISTANT: Ok.

USER: So I want you to change my existing reservation.

ASSISTANT: Sure, we are here to help you. Please, stay online.

USER: Sure.

ASSISTANT: Thank you for your valuable time. We are sorry to inform you that, no reservation was found on your name.

USER: Ok, not an issue. Thank you for your support.

ASSISTANT: Thank you for reaching us, have a good day.