formatDuration: function (d)

{

    // mette lo 0 a min o sec se < 9

    function adjustData()

    {

        if (arguments.length == 1)

        {

            var w = arguments[0];

            w = w > 9 ? w : "0" + w;

            return { sec: w };

        }

        else if (arguments.length == 2)

        {

            var w = arguments[0];

            var z = arguments[1];

            w = w > 9 ? w : "0" + w;

            z = z > 9 ? z : "0" + z;

            return { min: z, sec: w };

        }

    }

    var empty_data = "00:00:00 / ";

    var data = "";

    var dur = document.getElementById("c_text_and_duration");

    var d_calc = !d ? PLAYER.video_element.currentTime : d;

    d_calc = Math.round(d_calc); // arrotonda

    if (d_calc < 60) // secondi

    {

        d_obj = adjustData(d_calc);

        data = !d ? ("00:00:" + d_obj.sec + " / " + PLAYER.video_duration) :

                   empty_data + "00:00:" + d_obj.sec;

        if (d)

            PLAYER.video_duration = "00:00:" + d_obj.sec;

    }

    else if (d_calc < 3600) // minuti

    {

        var sec = d_calc % 60;

        var min = Math.floor(d_calc / 60);

        d_obj = adjustData(sec, min);

        data = !d ? ("00:" + d_obj.min + ":" + d_obj.sec + " / " + PLAYER.video_duration) :

            empty_data + "00:" + d_obj.min + ":" + d_obj.sec;

        if (d)

            PLAYER.video_duration = "00:" + d_obj.min + ":" + d_obj.sec;

    }

    else // ore

    {

        var h = Math.floor(d_calc / 3600);

        var m_t = d_calc % 3600;

        var m = Math.floor(m_t / 60);

        var s = m_t % 60;

        d_obj = adjustData(s, m);

        data = !d ? (h + ":" + d_obj.min + ":" + d_obj.sec + " / " + PLAYER.video_duration) :

            empty_data + h + ":" + d_obj.min + ":" + d_obj.sec;

        if (d)

            PLAYER.video_duration = h + ":" + d_obj.min + ":" + d_obj.sec;

    }

    dur.innerHTML = data;

}