(function($) {
    $.randomImage = { defaults: {
        path: 'images/',
        myImages: ['image1.jpg', 'image2.jpg']
    }
    }
    $.fn.extend({
        randomImage: function(config) {
            var config = $.extend({}, $.randomImage.defaults, config);
            return this.each(function() {
                var imageNames = config.myImages;
                var imageNamesSize = imageNames.length;
                var lotteryNumber = Math.floor(Math.random() * imageNamesSize);
                var winnerImage = imageNames[lotteryNumber];
                var fullPath = config.path + winnerImage;
                $(this).attr({
                    src: fullPath,
                    alt: winnerImage
                }).hide().fadeIn(500);
            });
        }
    });
})(jQuery);