You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

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

ASSISTANT: Yes, I am willing to help you. Can I know your name to check the reservation list?

USER: Jeffrey Collins.

ASSISTANT: Ok, please wait a minute I will get back to you.

USER: Sure.

ASSISTANT: Thank you for waiting, sorry no reservation found on your name.

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

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