JS控制视频播放器的代码

Question

// JavaScript Document
var control;
function showPlayer(url){//播放代码
var fileType=new Array();
fileType[0] =new Array(".mpg", ".mpeg",".asf",".wmv",".mp4");//MP 视频
fileType[1] =new Array(".mid",".mmf",".mp3",".wav",".midi",".wma");//MP 音频
fileType[2] =new Array(".rm",".rmvb");//RP 视频
fileType[3] =new Array(".amr");//RP 音频
fileType[4] =new Array(".3gp",".3gpp");//3GP 视频 var playerType = -1;
lastname = url.substring(url.lastIndexOf("."),url.length);
lastname = lastname.toLowerCase(); for(j=0;j<=fileType.length;j++){
for (i = 0; i < fileType[j].length; i++) {
if (fileType[j][i] == lastname) {playerType=j;break;}
}
if(playerType > -1)break;
} if(playerType==0)
document.write('<embed id="mediaplay" type="application/x-mplayer2" pluginspage="http://www.microsoft.com/Windows/Downloads/Contents/Products/MediaPlayer/" volume=100 src="'+url+'" width=280 height=255 showstatusbar=false showcontrols="true" controls="ControlPanel" autostart="true"></embed>');
else if(playerType==1)
document.write('<embed id="mediaplay" type="application/x-mplayer2" pluginspage="http://www.microsoft.com/Windows/Downloads/Contents/Products/MediaPlayer/" volume=100 src="'+url+'" width=280 height=69 displaysize=0 showdisplay=false showstatusbar=true showcontrols="true" autostart="true"></embed>');
else if(playerType==2)
document.write('<embed id="real" type="audio/x-pn-realaudio-plugin" src="'+url+'" width=280 autostart="true" loop="true" repeat="true" controls="ImageWindow,ControlPanel" height=251></embed>');
else if(playerType==3)
document.write('<embed id="real" type="audio/x-pn-realaudio-plugin" src="'+url+'" width=280 autostart="true" loop="true" repeat="true" controls="ControlPanel,StatusBar" height=60></embed>');
else if(playerType==4)
document.write('<embed id="quicktime" type="video/quicktime" pluginspage="http://www.apple.com/quicktime/download/index.html" volume=100 src="'+url+'" width=180 height=155 showstatusbar=false showcontrols="true" autostart="true" palette="transparent"></embed>');
else
document.writeln('文件扩展名不支持!');

}
function greateControl(){
control = document.getElementById('mediaplay');
}function doStop() {
control.stop();
}为了兼容FF浏览器使用了embed标签来控制视频插件，但发现JS不能想控制OBJECT标签一样得到插件的control。如何才能用embed的标签来控制插件的control.谢谢了