You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

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

ASSISTANT: Sure, we are happy to help you. May I know your good name?

USER: I am Nancy Thompson.

ASSISTANT: Sorry, there is no active reservation on your name in our records.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for contacting us.