You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

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

ASSISTANT: Sure, can I have your good name to check the reservation status?

USER: I am Charles Lee.

ASSISTANT: Please wait for a minute.

USER: Sure.

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

USER: That's ok, not a problem, thank you.

ASSISTANT: Thank you for choosing us.