You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: Due to some personal work, I want to change my existing reservation. Can you please change my reservation?

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

ASSISTANT: May I know your name?

USER: I am Carol Thompson.

ASSISTANT: Sorry, no reservation found with your name.

USER: Ok, Thank you for your help.

ASSISTANT: Thank you.