You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I am Shirley White. Please change my existing reservation, because I need to replace my business. So, can you help me in change in existing reservation?

ASSISTANT: OK, please wait.

USER: Sure.

ASSISTANT: There is no reservation found with your name.

USER: Ok. Thank you.

ASSISTANT: Have a good day.