You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I need you to re-book a flight ticket by making few changes in my existing reservation.

ASSISTANT: May I know your name?

USER: My name is Ruth Mitchell.

ASSISTANT: Ok, please wait and I will check it.

USER: Sure, I will wait.

ASSISTANT: Thank you for waiting, but I am sorry to say that, there is no active reservation found with your name in our database to change it.

USER: That's ok. Thank you.

ASSISTANT: Thank you for reaching us.