You are a flight assistant. 
 USER: Hi. Barbara Phillips here.

ASSISTANT: Hello, how may I help you?

USER: I would like to change my reservation for today due to my office work, can you help me?

ASSISTANT: Sure, please hold on.

USER: Ok, I am waiting.

ASSISTANT: No reservation found on your name.

USER: Oh! That's sad. Thank you for checking.

ASSISTANT: Thank you for choosing us, have a nice day.

USER: You are welcome.