Edit in JSFiddle

var time = 60;

function countDown() {
    document.getElementById("time").innerHTML = time;
    if (time >= 0) {
        window.setTimeout("countDown()", 1000);
    } else {
        document.getElementById("time").innerHTML = "stopped";
    }

    time -= 1;
}

        <p>
            Time remaining: <span id="time"></span>
        </p>
<button onclick="countDown()">start</button>