(function($) {
    $.fn.extend({
        elastic: function() {

            var mimics = new Array('paddingTop', 'paddingRight', 'paddingBottom', 'paddingLeft', 'fontSize', 'lineHeight', 'fontFamily', 'width');
            return this.each(function() {

                if (this.type == 'textarea') {

                    var textarea = $(this);
                    var minheight = parseInt(textarea.css('height'));
                    var marginbottom = parseInt(textarea.css('lineHeight')) * 2 || parseInt(textarea.css('fontSize')) * 2;
                    var goalheight = 0;
                    var twin = null;

                    function update() {
                        if (!twin) {
                            twin = $('<div />').css({ 'visibility': 'hidden', 'position': 'absolute', 'overflow-x': 'hidden' }).appendTo('body');
                            $.each(mimics, function() {
                                twin.css(this, textarea.css(this));
                            });
                        }


                        var content = textarea.val().replace(/<|>/g, ' ').replace(/\n/g, '<br />');
                        if (twin.text() != content) {
                            twin.html(content);
                            goalheight = (twin.height() + marginbottom > minheight) ? twin.height() + marginbottom : minheight;
                            if (goalheight != textarea.height())
                                textarea.css('height', goalheight);
                            //textarea.animate({ 'height': goalheight }, 500);
                        }
                    }
                    //textarea.css({overflow: 'hidden', display: 'block'}).bind('focus', function() { self.periodicalUpdater = window.setInterval(function() {update()}, 400); }).bind('blur', function() { clearInterval(self.periodicalUpdater); });
                    //update();

                    textarea.css('overflow', 'hidden').keydown(update).keyup(update).change(update);
                    update();
                }
            });
        }
    });
})(jQuery);