You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you now?

USER: Can you please help me to change my existing reservation?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: May I know your good name?

USER: I am Anna Parker.

ASSISTANT: Thank you for your name, sorry there is no reservation found on your name in our system data to change it.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for visiting us, we hope see you again.