You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how can I be your helping hand?

USER: My name is Jeffrey Turner. I need to change my existing reservation.

ASSISTANT: Sure, wait for a while.

USER: Ok.

ASSISTANT: I will check is there any reservation on your name and get back to you. Sorry to inform you that we did not find any reservation on your name.

USER: Thanks for the assistance.

ASSISTANT: Thank you for approaching us.