You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Raymond Thompson.

ASSISTANT: Let us know, How can I be of your service today?

USER: I want to change my existing reservation, please help me out.

ASSISTANT: Sure, I can help you.

USER: Ok.

ASSISTANT: Please wait for a couple of minutes.

USER: Sure, take your time.

ASSISTANT: Sorry Raymond Thompson, there is no active reservation on your name to change it.

USER: No issues, thanks for the response.

ASSISTANT: Thanks for approaching us.