You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, In what way shall 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: Sure, can I know your good name please?

USER: I am Helen Allen.

ASSISTANT: Ok, please wait for a minute.

USER: Sure.

ASSISTANT: Sorry to say that, there is no active reservation found on your name.

USER: No problem, thanks for the information.

ASSISTANT: Thank you for choosing us.