播放器的js檔

這是我寫的js程式碼

程式碼如下：

// JavaScript Document
var currentFile="";
//目前播放中的音樂

function playAudio()
{
//音樂的元素支援
if (window.HTMLAudioElement)
{ try { var Audio=document.getElementById('myaudio');
var bt=document.getElementById('play');
var audioURL=document.getElementById('playlist');
//Skip loading if current file hasn't changed.
if (audioURL.value!==currentFile)
{ Audio.src=audioURL.value;
currentFile=audioURL.value;
}

//Tests the paused attribute and set state.
if(Audio.paused) {
Audio.play();
bt.textContent="Pause";
}
else if(Audio.played) {
Audio.pause();
bt.textContent="Play";
}
}
catch(e){
// Fail silently but show in F12 developer tools console
if(window.console&&console.error("Error:"+e));
}
}
}

//停止播放
function AudioStop()
{
var Audio=document.getElementById('myaudio');
var bt=document.getElementById('play');
var lb=document.getElementById('playlist');
Audio.src=lb.value;
Audio.pause();
Audio.currentTime=0;
bt.textContent="Play";
}

//前一首歌
function Previous()
{
var Audio=document.getElementById('myaudio');
//var bt=document.getElementById('play');
var lb=document.getElementById('playlist');
var curfile=lb.value;
var len=24;

for(i=0;i<len;i++)
if(curfile==lb.options[i].value){
if(i!=0){ //檢查第一首歌
j=i-1; //指到前一首歌
Audio.src=lb.options[j].value;
if(Audio.paused){ Audio.play(); document.getElementById('play').textContent="Pause"; }
else if(Audio.played){ Audio.pause(); document.getElementById('play').textContent="Play"; }
lb.options[j].selected=true;
}
else{ //若是第一首歌
bt.textContent="Play/Pause";
}
}
}

//下一首歌
function Next()
{
var Audio=document.getElementById('myaudio');
//var bt=document.getElementById('play');
var lb=document.getElementById('playlist');
var curfile=lb.value;
var len=24;

if(curfile!=lb.options[len-1].value){
for(i=0;i<len;i++)
if(curfile==lb.options[i].value){
if(i!=len){ //檢查最後一首歌
j=i+1; //指到下一首歌
Audio.src=lb.options[j].value;
if(Audio.paused){ Audio.play(); document.getElementById('play').textContent="Pause"; }
else if(Audio.played){ Audio.pause(); document.getElementById('play').textContent="Play"; }
lb.options[j].selected=true;
}
}
}
else{ //若是最後一首歌
bt.textContent="Play/Pause";
}
}


大家好

如果我按previous鍵或next鍵

前一首歌或下一首歌會自動播放

然後我按下pause鍵

這首歌會重新播放且按鈕的內容還是pause

要如何解決這個問題

徵求高手協助

並告訴我要改哪邊

感激不盡