Recent penetration of smartphones has made audience participation in live electronics pieces easily possible. The piece played by the author at Csound Conference 2013 is based on the data sent from audience by using their own smartphones or tablets without having to install any dedicated app. The system uses a WiFi router for accepting connection from each participant, and a Linux laptop that runs Csound and lighttpd. By performing XMLHttpRequest data transmissions from the smartphone browsers, OSC message is generated by a PHP script to control Csound. This paper describes the system configuration for the piece. The revised system that additionally includes processing by HTML5 Web Audio API and Websocket that were added to enhance feedback to each participant is also described.