You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I would like to change my flight reservation as I met with an accident. Please help me.

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: May I know your name?

USER: I am Joseph Allen.

ASSISTANT: There is no reservation found under your name.

USER: No problem, thank you for checking.

ASSISTANT: Thank you for choosing us.