You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I oblige you today?

USER: Owing to an emergency, my meeting with client has been postponed. So I request you to change my existing reservation.

ASSISTANT: Sure, may I have your name please?

USER: Sure, I have a recent reservation with name Debra Wilson.

ASSISTANT: Ok, please hold on a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, no active reservation found on your name.

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

ASSISTANT: Thank you for choosing us.