You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I best serve you today?

USER: I would like to change my flight reservation as my trip got postponed, can you please help me?

ASSISTANT: Sure. May I know your name for further proceeding?

USER: Nancy Thompson.

ASSISTANT: Wait a moment.

USER: Ok.

ASSISTANT: I am sorry to say you that there is no reservation found under your name in our database.

USER: Not an issue, thank you for the service.

ASSISTANT: Thanks for reaching us.