怎么用JavaScript判断客户端浏览器是否安装了Flash插件，及其版本

如何用JavaScript判断客户端浏览器是否安装了Flash插件，及其版本？
<SCRIPT  LANGUAGE="JavaScript"> 
<!-- 
var  swf  =  new  ActiveXObject('ShockwaveFlash.ShockwaveFlash'); 
(swf)  ?  document.writeln('你已经安装了插件')  :  document.writeln('你没有安装插件'); 
//  --> 
</SCRIPT>




**************************************************************************
<script type="text/javascript" language="JavaScript">
<!-- start JS detection
FlashMode = 0;
if (navigator.plugins && navigator.plugins.length > 0)
{
    if (navigator.plugins["Shockwave Flash"])
    {
        var plugin_version = 0;
        var words = navigator.plugins["Shockwave Flash"].description.split(" ");
        for (var i = 0; i < words.length; ++i)
        {
            if (isNaN(parseInt(words[i])))
            continue;
            plugin_version = words[i];
        }
        if (plugin_version >= 5)
        {
            var plugin = navigator.plugins["Shockwave Flash"];
            var numTypes = plugin.length;
            for (j = 0; j < numTypes; j++)
            {
                mimetype = plugin[j];
                if (mimetype)
                {
                    if (mimetype.enabledPlugin && (mimetype.suffixes.indexOf("swf") != -1))
                        FlashMode = 1;
                    // Mac wierdness
                    if (navigator.mimeTypes["application/x-shockwave-flash"] == null)
                        FlashMode = 0;
                }
            }
        }
    }
}
if (FlashMode == 1)
{
document.write('有FLASH的HTML');}
else {
document.write('无FLASH的HTML'); }