var timeoutID;

function setup() {
    this.addEventListener("mousemove", resetTimer, false);
    this.addEventListener("mousedown", resetTimer, false);
    this.addEventListener("keypress", resetTimer, false);
    this.addEventListener("DOMMouseScroll", resetTimer, false);
    this.addEventListener("mousewheel", resetTimer, false);
    this.addEventListener("touchmove", resetTimer, false);
    this.addEventListener("MSPointerMove", resetTimer, false);

    startTimer();
}
setup();

function startTimer() {
    // wait 2 seconds before calling goInactive
    timeoutID = window.setTimeout(goInactive, 2000);
}

function resetTimer(e) {
    window.clearTimeout(timeoutID);

    goActive();
}

function goInactive() {
    // do something
}

function goActive() {
    // do something

    startTimer();
}