You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you today?

USER: I need to change my existing reservation, due to sudden change in my plan. Can you please help me to change it?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: May I know your name?

USER: Sure, my name is Stephanie Carter.

ASSISTANT: Please wait for a moment.

USER: Sure.

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

USER: Ok, no problem. Thank you.

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