Yeah I would do something like this: http://stackoverflow.com/a/7942472 and link it to a button @haloniko
// Initial volume of 0.20
// Make sure it's a multiple of 0.05
var vol = 0.20;
var interval = 200; // 200ms interval
var fadeout = setInterval(
function() {
// Reduce volume by 0.05 as long as it is above 0
// This works as long as you start with a multiple of 0.05!
if (vol > 0) {
vol -= 0.05;
audio.setVolume(vol);
}
else {
// Stop the setInterval when 0 is reached
clearInterval(fadeout);
}
}, interval);