You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: Due to inconvenience of my work, I want to change my reservation. Can you please help me for that?

ASSISTANT: Sure, I am here to help you out.

USER: Thanks.

ASSISTANT: May I know your name please?

USER: My name is Alexander Scott.

ASSISTANT: Alexander Scott, we regret to inform you that there is no reservation found on your name in our records.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for choosing us.