You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Can you aid me to cancel my reservation due to emergency?

ASSISTANT:  Sure, I am here to help you. May I know your name to check with existing reservation?

USER: Donald Turner here.

ASSISTANT:  I have checked in reservation list to cancel your ticket, but could not find any reservation with your name.

USER: Thank you for the help.

ASSISTANT: Thank you for choosing us.