问音频播放器上显示2个十进制时间

EN

var duration = document.getElementById('fullDuration');
var currentTime = document.getElementById('currentTime');

duration.innerHTML = mytrack.duration;


mytrack.addEventListener("loadedmetadata",function(){
    var minutes = parseInt(mytrack.duration / 60);
    var seconds = parseInt(mytrack.duration % 60);
    duration.innerHTML = minutes + ':' + seconds;
})

function update(){
  if(!mytrack.ended){
    var playedMinutes = parseInt(mytrack.currentTime/60);
    var playedSeconds = parseInt(mytrack.currentTime%60);
    currentTime.innerHTML = playedMinutes + ':' + playedSeconds;

    var size = parseInt(mytrack.currentTime*barSize/mytrack.duration);
    progressBar.style.width = size + "px";

  }
  else{
    currentTime.innerHTML = "0.00";
    playButton.style.backgroundImage = 'url(file:///Users/Pier/Desktop/Play%20button.png)';
    progressBar.style.width = "0px";
    window.clearInterval(updateTime);
  }
}