You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

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

ASSISTANT: Ok, may I know your good name for changing?

USER: Sure, I have a recent reservation with name Jennifer Smith.

ASSISTANT:  Please wait I will revert you in a moment.

USER: Sure.

ASSISTANT:  Sorry to inform you that no reservation was found on your name in our data base.

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

ASSISTANT:  Thank you for availing us.