检测是否安装或者开启flash

function flashChecker() {
    var hasFlash = 0;　　　　 //是否安装了flash
    var flashVersion = 0;　　 //flash版本
    if(document.all) {
        var swf = new ActiveXObject('ShockwaveFlash.ShockwaveFlash');
        if(swf) {
            hasFlash = 1;
            VSwf = swf.GetVariable("$version");
            flashVersion = parseInt(VSwf.split(" ")[1].split(",")[0]);
        }
    } else {
        if(navigator.plugins && navigator.plugins.length > 0) {
            var swf = navigator.plugins["Shockwave Flash"];
            if(swf) {
                hasFlash = 1;
                var words = swf.description.split(" ");
                for(var i = 0; i < words.length; ++i) {
                    if(isNaN(parseInt(words[i]))){
                        continue;
                    }
                    flashVersion = parseInt(words[i]);
                }
            }
        }
    }
    return {
        f: hasFlash,
        v: flashVersion
    };
}
var fls = flashChecker();
if(fls.f){
     document.write("您安装了flash,当前flash版本为: " + fls.v + ".x");
}else {
    document.write("您没有安装flash");
};

　　

来源：http://www.cnblogs.com/xuan52rock/p/11466559.html