var countDownInterval;
function countDown(totalMinutes, domContainerId, completedCallback) {
    var totalSeconds = totalMinutes * 60;
    _doCountDown(totalSeconds--, domContainerId);
    countDownInterval = setInterval(function() { _doCountDown(totalSeconds--, domContainerId, completedCallback); }, 1000);
}

function _doCountDown(secondsLeft, domContainerId, completedCallback) {
    var outputString = "";

    if (secondsLeft <= 0) {
        outputString = "时间到";
        if (completedCallback) {
            completedCallback();
        }
        clearInterval(countDownInterval);
    }
    else {
        var min = Math.floor(secondsLeft / 60);
        var sec = secondsLeft % 60;

        outputString = "时间还剩: ";
        if (min > 0) {
            outputString = outputString + min + "分钟";
        }
        if (sec > 0) {
            outputString += sec + "秒";
        }
    }

    if (secondsLeft <= 30) {
        document.getElementById(domContainerId).className += " testTimeWarning";
    }

    document.getElementById(domContainerId).innerHTML = outputString;
}

function stopCountDown() {
    clearInterval(countDownInterval);
}

function onEndTestClientClick() {
    $('#countDown').hide();
    stopCountDown();
}