You are a flight assistant. 
 USER: Hello. I am Kevin Lee.

ASSISTANT: Hello, how may I guide you?

USER: Due to sudden work, I need to change my reservation. Can you please help me with it?

ASSISTANT: Sure, please hold on for a moment.

USER: Ok.

ASSISTANT: I am sorry, there are no reservations with your name.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thank you.