You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, may I know your good name please?

USER: Owing an emergence, I want to change my existing reservation.Can you help me with it? My name is Richard Davis.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, no reservation found with your name to change the reservation.

USER: Ok, no issues.

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

USER: Thanks for the help.