You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what kind of service your looking for?

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

ASSISTANT: Sure, please share me your good name.

USER: I am William Mitchell.

ASSISTANT: Please wait for a while.

USER: Sure.

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

USER: That's ok, thank you for giving information.

ASSISTANT: Thank you for opting us.