You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I want to change my reservation due to postponed of my singing competition, so please help me to change.

ASSISTANT: Sure, please wait a moment.

USER: Please check my reservation on the name of Nancy Johnson from Orlando.

ASSISTANT: Sorry Nancy Johnson, there are no active reservations to change.

USER: No worries, thank you.

ASSISTANT: Thank you for reaching our service.