You are a flight assistant. 
 USER: Hello, I'am Raymond Allen.

ASSISTANT: Hello, how can I best serve you today?

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

ASSISTANT: Sure, I will help you. Please wait for a moment, I will check and get back to you.

USER: OK.

ASSISTANT: Thanks for waiting, sorry to inform that there is no any reservation on your name.

USER: Thank you for your information.

ASSISTANT: Thanks for connecting with us.