怎样用js控制媒体播放器控件

<HTML>
    <object classid="clsid:6BF52A52-394A-11D3-B153-00C04F79FAA6" id="shyslysky" width="245" height="240" VIEWASTEXT>
    <param name="URL" value="http://msdn.microsoft.com/workshop/samples/author/behaviors/media/28movie.asf">
    <param name="balance" value="0">
    <param name="currentPosition" value="0">
    <param name="defaultFrame" value>
    <param name="playCount" value="1">
    <param name="autoStart" value="-1">
    <param name="currentMarker" value="0">
    <param name="invokeURLs" value="-1">
    <param name="baseURL" value>
    <param name="volume" value="50">
    <param name="mute" value="0">
    <param name="uiMode" value="full">
    <param name="stretchToFit" value="0">
    <param name="windowlessVideo" value="0">
    <param name="enabled" value="-1">
    <param name="enableContextMenu" value="-1">
    <param name="fullScreen" value="0">
    <param name="SAMIStyle" value>
    <param name="SAMILang" value>
    <param name="SAMIFilename" value>
    <param name="captioningID" value>
    <param name="enableErrorDialogs" value="0">
    <param name="_cx" value="6482">
    <param name="_cy" value="6350">
  </object>
</p>
<input type=button value=mute onclick=shyslysky.settings.mute=shyslysky.settings.mute==true?false:true;time.innerText=shyslysky.settings.mute==true?'静音':'关闭静音'; ID="Button1" NAME="Button1">
<input type=button value=play onclick=shyslysky.controls.play();time.innerText='播放'; ID="Button2" NAME="Button2">
<input type=button value=pause onclick=shyslysky.controls.pause();time.innerText='暂停'; ID="Button3" NAME="Button3">
<input type=button value=stop onclick=shyslysky.controls.stop();time.innerText='停止'; ID="Button4" NAME="Button4">
<input type=button value=mode onclick=shyslysky.settings.balance=shyslysky.settings.balance=='100'?'-100':'100';time.innerText=shyslysky.settings.balance=='100'?'右声道':'左声道'; ID="Button5" NAME="Button5">
<input type=button value=vol++ onclick=volup(); ID="Button6" NAME="Button6">
<input type=button value=vol-- onclick=voldown(); ID="Button7" NAME="Button7">
<input type=button value=fullscreen onclick="if(shyslysky.playState==3)shyslysky.fullscreen=1;" ID="Button8" NAME="Button8">
<br>
<div id="time" style="background:#f2f3f7;width:245">正在加载媒体</div>
<table id=bar style="width:245;height:10px;border:1px black solid;">
  <tr> 
    <td id=itcn bgcolor=#f70968 style="width:0"></td>
    <td id=bar2 style="width:245"></td>
  </tr>
</table>
<script language=javascript>
var volv=shyslysky.settings.volume;
setInterval("if(shyslysky.playState==3){time.innerText=shyslysky.controls.currentPositionString+'|'+shyslysky.currentMedia.durationString}",1000);
setInterval("if(shyslysky.playState==3){itcn.style.width=parseInt(245*(shyslysky.controls.currentPosition/shyslysky.currentMedia.duration))}",1000);
function volup(){
if (volv<100){
volv+=5;
shyslysky.settings.volume=volv;
time.innerText=volv;}
else{time.innerText='最大';}
}
function voldown(){
if (volv>0){
volv-=5;
shyslysky.settings.volume=volv;
time.innerText=volv;}
else{time.innerText='最小';}
}
</script>
 
</HTML>