(function( $ ) {

    // extending jQuery
    $.fn.extend({
        tagName: function(){
            if(1 === this.length){
                return this[0].tagName.toLowerCase();
            } else{
                var tagNames = [];
                this.each(function(i, el){
                        tagNames[i] = el.tagName.toLowerCase();
                });
                return tagNames;
            }
        }
   });
})(jQuery);