You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you at this moment?

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

ASSISTANT: Sure, I am happy to help you with that.

USER: Thank you.

ASSISTANT: Can I have your good name please to check your reservation status?

USER: I am Ruth Hall.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry Ruth Hall, no reservation  has found under your name to change.

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

ASSISTANT: Thank you for choosing us, have a good day.