/*
    - a javascript frontend server backend that connects to mqtt broker and subscribes to 'msg/Upload' topic
    - this server have can receive websocket connections and 
    
    - this server can also serve a static webpage that connects to the websocket server
    - once a message is received from the mqtt broker. the message will be send to the websocket client (static page loaded by the webbrowser) for display.
    - the static webpage should popup a notification and disappear after 3 seconds.

*/ Write your response with exactly 6 paragraphs, separated with the markdown divider: ***.
user