js 行: 176 错误: 'currentMedia.duration' 为空或不是对象 红色代码为176行

<!--
var isPorV = 0;
var fFlag= false;

//drag func
var pFlag = false;
var pZoneWidth = 129;
var infoChange = 1;

var bufferingProgress;
var downloadProgress;
var bitRate;
var currentPositionString;
var mediaTitle;
var itemTitle;
var mediaInfo;

function getOLeft(myObj){
curObj = myObj;
var objLT = curObj.offsetLeft;
while(curObj!=curObj.offsetParent && curObj.offsetParent) {
curObj=curObj.offsetParent;
if(curObj.tagName=="DIV") {
objLT += curObj.offsetLeft;
}
}
return objLT;
}

//truncation string
function trunStr(str) {
if (str.length > 35){
return str.substr(0,35) + "...";
}
else{
return str;
}
}

function toPlay() {
if ($("MediaPlayer").playState != 3) {
if ($("MediaPlayer").controls.isAvailable('Play')) {
$("MediaPlayer").controls.play();
$("Play").src="mediaplayer/lightblue/p_play1.gif";
toDisplay(1);
}
}
else {
toPause();
}
}

function toPause() {
if ($("MediaPlayer").currentMedia.duration > 0) {
infoChange = 1;
$("MediaPlayer").controls.Pause();
$("Play").src="mediaplayer/lightblue/p_play.gif";
}
}

function toStop() {
if ($("MediaPlayer").currentMedia.duration > 0) {
$("MediaPlayer").controls.Stop();
$("Play").src="mediaplayer/lightblue/p_play.gif";
toDisplay(0);
}
}

function toScreen(){
$("MediaPlayer").fullScreen=1;
}

function toMute(){
if($("MediaPlayer").settings.mute){
$("MediaPlayer").settings.mute = false;
$('Mute').src='mediaplayer/lightblue/p_mute.gif';
}
else{
$("MediaPlayer").settings.mute = true;
$('Mute').src='mediaplayer/lightblue/p_mute1.gif';
}
}

function toDisplay(v){
var P=$("playzone").getElementsByTagName("div");
if(v){
P[0].style.display='none';
P[1].style.display='block';
}
else{
P[1].style.display='none';
P[0].style.display='block';
}
}

function mouseDown(objSign) {
isPorV = objSign;
if(isPorV == 0) {
if($("MediaPlayer").currentMedia.duration > 0) {
pFlag = true;
if(window.event.srcElement.id!="pZone") {
$("pBox").style.left = $("pBox").offsetLeft -1;
}
else {
$("pBox").style.left = window.event.x;
}
}
}
else if (isPorV == 1) {
vFlag = true;
//alert($("vBox").offsetLeft);
if(window.event.srcElement.id!="vZone") {
$("vBox").style.left = $("vBox").offsetLeft;
}
else {
$("vBox").style.left = window.event.x;
}
}
}

function mouseMove() {
if(isPorV == 0) {
if($("MediaPlayer").currentMedia.duration > 0) {
if (pFlag)
$("pBox").style.left = window.event.clientX - getOLeft($("pZone")) - 12 +"px";
if (parseInt($("pBox").style.left.replace("px","")) > pZoneWidth)
$("pBox").style.left=pZoneWidth +"px";
if (parseInt($("pBox").style.left.replace("px","")) < -5)
$("pBox").style.left=-5 +"px";
}
} else if (isPorV == 1) {
if(vFlag) $("vBox").style.left = window.event.clientX - getOLeft($("vZone")) - 4 +"px";
if (parseInt($("vBox").style.left.replace("px","")) > 46) $("vBox").style.left = 44 +"px";
if (parseInt($("vBox").style.left.replace("px","")) < 1) $("vBox").style.left = 1 +"px";

if(isPorV==1) {
if (vFlag){
tempVol = (parseInt($("vBox").style.left) - 4)*5.9;
$("MediaPlayer").settings.volume=Math.round(tempVol);
$("MediaPlayer").settings.mute = false;
$('Mute').src='mediaplayer/lightblue/p_mute.gif';
}
}
}
}

function mouseUp() {
if (isPorV == 0) {
if($("MediaPlayer").currentMedia.duration > 0) {
if (pFlag) {
var duration = $("MediaPlayer").currentMedia.duration;
$("MediaPlayer").controls.CurrentPosition=duration * (parseInt($("pBox").style.left)/pZoneWidth);
}
pFlag = false;
}
} else if (isPorV == 1) {
if (vFlag) {
tempVol = (parseInt($("vBox").style.left) -9)*1.7;
$("MediaPlayer").settings.volume=Math.round(tempVol);
}
vFlag = false;
}
}

function mouseEnd() {
window.event.returnValue = false;
}

function OnloadFun() {
mediaInfo = $("mediaInfo");
startdrag();
setInterval("FixPos()", 1000);
}

function startdrag() {
if($("MediaPlayer").currentMedia.duration||(!isNaN($("MediaPlayer").currentMedia.duration))) { window.document.onmousemove = mouseMove;
window.document.ondragstart = mouseEnd;
window.document.onmouseup = mouseUp;
}
}

function FixPos() {
if ($("MediaPlayer").currentMedia.duration > 0) {
var duration = $("MediaPlayer").currentMedia.duration;
var pos = $("MediaPlayer").controls.CurrentPosition;
if (pos == 0) {
var pBoxPos = Math.round(pos/duration*pZoneWidth)+1;
} else {
var pBoxPos = Math.round(pos/duration*pZoneWidth)+1;
}

if (!isNaN(pBoxPos)) {
$("pBox").style.left = pBoxPos;
}

if($("MediaPlayer").playState == 1) {
$("pBox").style.left = 1;
mediaInfo.innerHTML="<a href='mailto:haixiao_yao@yahoo.com.cn' class='cWhite' target='_blank'>�޲��ع�����</a>�����춼���ʣ�";
$("Play").src="mediaplayer/lightblue/p_play.gif";
toDisplay(0);
}

bufferingProgress = $("MediaPlayer").network.bufferingProgress;
downloadProgress = parseInt($("MediaPlayer").network.downloadProgress);
bitRate = $("MediaPlayer").network.bitRate;
currentPositionString = $("MediaPlayer").Controls.currentPositionString;
mediaTitle = $("MediaPlayer").currentPlaylist.item(0).getItemInfo("Title");
itemTitle = $("MediaPlayer").currentPlaylist.getItemInfo("Title");
$("mediaTime").innerText =' '+ currentPositionString.toString();

switch($("MediaPlayer").playState) {
case 7: {
mediaInfo.innerText="����";
}
break;

case 6: {
if ( parseInt(bufferingProgress) > 0 && parseInt(bufferingProgress) < 100 ) {
mediaInfo.innerText="����:���� "+bufferingProgress.toString()+"%";
} else {
mediaInfo.innerText="����";
}
}
break;

case 3: {
if ( downloadProgress == 0 ) {
mediaInfo.innerText="���ڲ���"; }
showPlayInfo();
}
break;
}
}
}

function showPlayInfo() {
if ( infoChange ==1 ) {
if ( downloadProgress < 100 ) {
mediaInfo.innerText="���ڲ���: "+downloadProgress.toString()+"% ������";
}
else {
mediaInfo.innerText="���ڲ���: "+Math.round(bitRate/1000)+" ǧ����/��";
}

if ( downloadProgress == 0 ) {
mediaInfo.innerText="���ڲ���";
}
}

if ( infoChange ==4 ) {
mediaInfo.innerText="����:"+itemTitle.toString();
}

if ( infoChange ==8 ) {
mediaInfo.innerText="����: "+trunStr(mediaTitle).toString();
}

if ( infoChange < 11 ) {
infoChange += 1;
}
else {
infoChange = 1;
}
}

setOnloadEvent(OnloadFun);