js 如何获取硬盘序列号呢？

 var locator = new ActiveXObject("WbemScripting.SWbemLocator");
    var service = locator.ConnectServer(".");
    var properties = service.ExecQuery("SELECT * FROM Win32_PhysicalMedia");
    var e = new Enumerator(properties);
    document.write("<table border=1>");
    for (; !e.atEnd() ; e.moveNext()) {
        var p = e.item();
        if (p.SerialNumber) {
            document.write("<tr>");
            document.write("<td>" + p.SerialNumber + "</td>");
            document.write("</tr>");
        }
    }