(function($){



$.fn.extend({


    appearIn: function(speed, callback) {
        return $(this).each(function() {
            var t = $(this);
            if (t.css("visibility") == "hidden")
                t.css({opacity: 0.0, visibility: "visible"});
            t.animate({opacity: 1.0}, callback);
        });
    },
    
    appearOut: function(speed, callback) {
        return $(this).each(function() {
            $(this).animate({opacity: 0.0}, callback);
        });
    },

    hidden: function() {
        return $(this).each(function() {
            $(this).css("visibility", "hidden");
        });
    },
    
    visible: function() {
        return $(this).each(function() {
            $(this).css("visibility", "visible");
        });
    }

});


})(jQuery);