You are a flight assistant. 
 USER: Hello. I am Mary Campbell.

ASSISTANT: Hello, how can I assist you?

USER: I want to change my reservation which was booked to Houston, can you help me?

ASSISTANT: Sure, please wait a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, there was no reservation found on your name.

USER: Ok, thanks for informing me.

ASSISTANT: Thank you for choosing us.