You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

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 please?

USER: Donald Garcia.

ASSISTANT: Please wait.

USER: Ok.

ASSISTANT: Thanks for waiting. But I am sorry to say that there is no flight reservation on your name to change it.

USER: Ok, thank you for the information.

ASSISTANT: Thank you.