You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you for today?

USER: Actually my Tennis competition is postponed so that I want to change my existing reservation, can you help me?

ASSISTANT: Sure, I am glad to help you. Please provide your name.

USER: Sure, I am Brian Miller.

ASSISTANT: Miller, in our database there is no ticket booked with your name.

USER: Ok, thank you for your information.

ASSISTANT: Thank you.