object 为html4 和html5共有的，embed，video 为html5新加的标签，
object和embed支持几乎所有的格式视频，但object只有IE浏览器支持，其他浏览器大都支持embed
所以把embed嵌入object实现多浏览器兼容。
video只支持三种格式的视频。ogg,mpeg4,,,
所以大多数视频播放都采用object内嵌embed
/**
*视频播放
*参数说明
u - 媒体URL
w - 媒体宽度width
h - 媒体高度height
*/
//播放Mediaplayer格式的视频，包括.avi .mpg .mpeg .wmv .wma .asf .mid .mp3等
function pv_m(u, w, h){
var pv='';
pv += '<object width="'+w+'" height="'+h+'" id="iask_v" classid="CLSID:22d6f312-b0f6-11d0-94ab-0080c74c7e95" codebase="http://activex.microsoft.com/activex/controls/mplayer/en/nsmp2inf.cab#Version=6,4,5,715" standby="Loading Microsoft Windows Media Player components..."
type="application/x-oleobject">';
pv += '<param name="FileName" value="'+u+'">';
pv += '<param name="AutoStart" value="1">';
pv += '<param name="AutoSize" value="1">';
pv += '<param name="ShowControls" value="1">';
pv += '<param name="ShowPositionControls" value="0">';
pv += '<param name="ShowAudioControls" value="1">';
pv += '<param name="ShowTracker" value="1">';
pv += '<param name="ShowDisplay" value="0">';
pv += '<param name="ShowStatusBar" value="1">';
pv += '<param name="ShowGotoBar" value="0">';
pv += '<param name="ShowCaptioning" value="0">';
pv += '<param name="PlayCount" value="1">';
pv += '<param name="AnimationAtStart" value="0">';
pv += '<param name="TransparentAtStart" value="0">';
pv += '<param name="AllowScan" value="0">';
pv += '<param name="EnableContextMenu" value="0">';
pv += '<param name="ClickToPlay" value="0">';
pv += '<param name="InvokeURLs" value="1">';
pv += '<param name="DefaultFrame" value="">';
pv += '<embed src="'+u+'" width="'+w+'" height="'+h+'" type="application/x-mplayer2" pluginspage="http://www.microsoft.com/isapi/redir.dll?prd=windows&;sbp=mediaplayer&ar=media&sba=plugin&" name="MediaPlayer" showcontrols="1" showpositioncontrols="0" showaudiocontrols="1"
showtracker="1" showdisplay="0" showstatusbar="1" autosize="0" showgotobar="0" showcaptioning="0" autostart="1" autorewind="0" animationatstart="0" transparentatstart="0" allowscan="1" enablecontextmenu="1" clicktoplay="0" invokeurls="1" defaultframe=""></embed>';
pv += '</object>';
document.write(pv);
}
//播放Realplay格式的视频，包括.rm .ram .rmvb等
function pv_r(u, w, h){
var pv='';
pv += '<object width="'+w+'" height="'+h+'" id="iask_v" classid="clsid:CFCDAA03-8BE4-11cf-B84B-0020AFBBCCFA">';
pv += '<param name="SRC" value="'+u+'">';
pv += '<param name="AUTOSTART" value="1">';
pv += '<param name="CONTROLS" value="Imagewindow,StatusBar,ControlPanel">';
pv += '<param name="_ExtentX" value="18415">';
pv += '<param name="_ExtentY" value="9102">';
pv += '<param name="SHUFFLE" value="0">';
pv += '<param name="PREFETCH" value="0">';
pv += '<param name="NOLABELS" value="0">';
pv += '<param name="CONSOLE" value="Clip1">';
pv += '<param name="LOOP" value="0">';
pv += '<param name="NUMLOOP" value="0">';
pv += '<param name="CENTER" value="0">';
pv += '<param name="MAINTAINASPECT" value="0">';
pv += '<param name="BACKGROUNDCOLOR" value="#000000">';
pv += '<embed src="'+u+'" width="'+w+'" height="'+h+'" type="audio/x-pn-realaudio-plugin" console="Clip1" controls="Imagewindow,StatusBar,ControlPanel" autostart="true">';
pv += '</object>';
document.write(pv);
}
//播放Quicktime格式的视频，包括.mov .amr .3gp等
function pv_q(u, w, h){
var pv='';
pv += '<object width="'+w+'" height="'+h+'" classid="clsid:02BF25D5-8C17-4B23-BC80-D3488ABDDC6B" codebase="http://www.apple.com/qtactivex/qtplugin.cab">';
pv += '<param name="src" value="'+u+'">';
pv += '<param name="controller" value="true">';
pv += '<param name="type" value="video/quicktime">';
pv += '<param name="autoplay" value="true">';
pv += '<param name="target" value="myself">';
pv += '<param name="bgcolor" value="black">';
pv += '<param name="pluginspage" value="http://www.apple.com/quicktime/download/index.html">';
pv += '<embed src="'+u+'" width="'+w+'" height="'+h+'" controller="true" align="middle" bgcolor="black" target="myself" type="video/quicktime" pluginspage="http://www.apple.com/quicktime/download/index.html"></embed>';
pv += '</object>';
document.write(pv);
}