$(document).ready(function () {
    $('#boxContent dt #powerPoint').attr('class', 'active');
    $('#boxContent dd').css('opacity', 0);
    $('#boxContent dd#txt_powerPoint').css('display', 'inline-block');
    $('#boxContent dd#txt_powerPoint').animate({
        opacity: '1'
    }, '500');

    $('#boxContent dt a').click(function () {
        var $id = $(this).attr('id');
        var $selected = "txt_" + $id;

        $('#boxContent dd').stop();

        $('#boxContent dd').each(function () {
            if ($selected != $(this).attr('id')) {
                $(this).css('opacity', 0);
                $(this).css('display', 'none');
                $('#boxContent dt a').attr('class', 'inactive');
            }
            else {
                $(this).css('display', 'none');
                $(this).css('display', 'inline-block');
                $(this).animate({
                    opacity: '1'
                }, '500');
            }
        });

        $('#boxContent dt #' + $id).attr('class', 'active');
        return false;
    });
});