document.addEvent('domready', function () {

    if ($('counter')) {

        var countdownTxt = '';
        var oneMin = 60 * 1000;
        var oneHr = oneMin * 60;
        var oneDay = oneHr * 24;

        // Exhibition start time - obtained from Config.Set in "CommonControls/Events/SITE_Page_Script.ascx"
        var d = new Date(Config.get('eventstartdate'));
        var start = Date.UTC(d.getFullYear(), d.getMonth(), d.getDate(), d.getHours(), d.getMinutes(), d.getSeconds(), d.getMilliseconds());

        var showCounter = (function () {
            // convert now time to milliseconds
            var now = new Date();
            now = now.getTime();

            // determine no. milliseconds until Exhibition starts and convert to days/hrs/mins
            var ems = start - now;
            var days = Math.floor(ems / oneDay);
            var hrs = Math.floor((ems - (days * oneDay)) / oneHr);
            var mins = Math.floor((ems - (days * oneDay) - (hrs * oneHr)) / oneMin);
            var secs = Math.floor((ems - (days * oneDay) - (hrs * oneHr) - (mins * oneMin)) / 1000);

            countdownTxt = '<span><strong>' + days + '</strong> days</span>';
            countdownTxt += ' <span><strong>' + hrs + '</strong> hours</span>';
            countdownTxt += ' <span><strong>' + mins + '</strong> mins</span>';
            countdownTxt += ' <span class="last"><strong>' + secs + '</strong> secs</span>';

            if (ems > 0)
                $('counter').set('html', countdownTxt);
            else
                $('countdown').destroy();
            $clear(showCounter);
        }).periodical(1000); // run every second

    }
});