You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

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

ASSISTANT: Sure, I am here to help you with this.

USER: Thank you.

ASSISTANT: May I know your good name please?

USER: I am Donna Nelson.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry Nelson, there is no reservation found as per your name to change it.

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

ASSISTANT: You are welcome.