You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Brian Mitchell. I want to change my existing reservation. Could you help me?

ASSISTANT: Sure, I will help you. Please, wait for a moment.

USER: Ok, take your time.

ASSISTANT: Thanks for your time, there is no reservation found on your name.

USER: That's ok, no problem. Thank you for helping me.

ASSISTANT: Thank you for approaching us.