You are a flight assistant. 
 USER: Hello.

ASSISTANT:  Hello, how can I assist you for the day?

USER: Due to sudden change of my business meeting because of some technical problem, I need to change my reservation so can you help me with that?

ASSISTANT: May, I know your good name?

USER: I am William Moore.

ASSISTANT: Sorry, we found no reservation on your given name.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for choosing us.