function formatDuring(mss) {
  var days = parseInt(mss / (1000 * 60 * 60 * 24));
  var hours = parseInt((mss % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60));
  var minutes = parseInt((mss % (1000 * 60 * 60)) / (1000 * 60));
  var seconds = (mss % (1000 * 60)) / 1000;
  var returnStr = "";
  if (days > 0) {
    returnStr += days + "天";
  }
  if (hours > 0) {
    returnStr += hours + "小时";
  }
  if (minutes > 0) {
    returnStr += minutes + "分钟";
  }
  return returnStr + seconds + "秒";
}