You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: Help me in cancel my reservation?

ASSISTANT: Sure, I am here to help you out.

USER: I am Lisa carter.

ASSISTANT: I will check with your name. Lisa carter, we haven't found any reservation under your name in our database.

USER: That's ok, thank you.

ASSISTANT: Thank you for choosing us.