You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you today?

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

ASSISTANT: Sure, we are here to help you. May I know your name please to proceed further?

USER: Sure, Rebecca Scott here.

ASSISTANT: Sorry to inform you that there is no active reservation found on your given name.

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

ASSISTANT: Thanks for contacting us, have a nice day.