[JAVASCRIPT] Up-counting Timer

var timer = document.getElementById("timer");
var t = {
    sec : 0,
    min : 0,
    hr  : 0,
}

setInterval(setTime, 1000);

function setTime() {
    t.sec++;

    if (t.sec == 60) {
        t.sec = 0;
        t.min++;
    }

    if (t.min == 60) {
        t.min = 0;
        t.hr++;
    }

    timer.innerHTML = pad(t.hr) + ":" + pad(t.min) + ":" + pad(t.sec);
}

function pad(i) {
    if (i <= 9)
        return "0" + i;
    else
        return i;
}