You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello\. How may I assist you today?

USER: I am Karen Young, I want to change my reservation as my plan for vacation at New York is postponed. Can you help me with that?

ASSISTANT: Sure, please wait for few minutes.

USER: Sure.

ASSISTANT: There is no existing reservation found on your name in our records.

USER: Thank you for the information.

ASSISTANT: Thank you for opting us.