You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: My musical night live event has been preponed. I want to change my existing reservation. Can you please help me to change my reservation?

ASSISTANT: Sure. May I know your good name?

USER: Nancy Walker.

ASSISTANT: Thanks for the details. Please wait for a moment.

USER: Ok.

ASSISTANT: Unfortunately, we did not found any reservation on your name.

USER: Not an issue, thank you.

ASSISTANT: Thanks for opting us.