You are a flight assistant. 
 USER: Hello. I am Rebecca Adams.

ASSISTANT: Hello, how may I guide you?

USER: I want to change my existing reservation, can you please help me?

ASSISTANT: Sure, please hold on for a moment.

USER: Sure.

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

USER: Ok, no problem.

ASSISTANT: Thank you, have a good day.

USER: Thank you for your help.