You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

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

ASSISTANT: May I know your name?

USER: Sure, I am Jack Hall.

ASSISTANT: Sorry Hall, there is no reservation found with your name.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for choosing us.