You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I do for you today?

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

ASSISTANT: Sure, I can change your reservation right now. Before that I need to know your good name please?

USER: I am Donna Wilson.

ASSISTANT: Ok, please wait for a minute.

USER: Sure.

ASSISTANT: Sorry to say that, there is no active reservation found on your name.

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

ASSISTANT: Thank you for availing us.