You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: Myself Betty Mitchell. I want to change my existing reservation, can you help me?

ASSISTANT: Sure Betty, please wait a moment.

USER: Sure.

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

USER: That's ok, no problem.

ASSISTANT: Thank you for approaching us.

USER: Thank you for the information.