(function(jQuery) {
    jQuery.fn.extend({
        elastic: function() {
            var mimics = ['paddingTop', 'paddingRight', 'paddingBottom', 'paddingLeft', 'fontSize', 'lineHeight', 'fontFamily', 'width', 'fontWeight'];
            return this.each(function() {
                if (this.type != 'textarea') {
                    return false
                }
                var $textarea = jQuery(this),
                $twin = jQuery('<div />').css({
                    'position': 'absolute',
                    'display': 'none',
                    'word-wrap': 'break-word'
                }),
                lineHeight = parseInt($textarea.css('line-height'), 10) || parseInt($textarea.css('font-size'), '10'),
                minheight = parseInt($textarea.css('height'), 10) || lineHeight * 1,
                maxheight = parseInt($textarea.css('max-height'), 10) || Number.MAX_VALUE,
                goalheight = 0,
                i = 0;
                if (maxheight < 0) {
                    maxheight = Number.MAX_VALUE
                }
                $twin.appendTo($textarea.parent());
                var i = mimics.length;
                while (i--) {
                    $twin.css(mimics[i].toString(), $textarea.css(mimics[i].toString()))
                }
                function setHeightAndOverflow(height, overflow) {
                    curratedHeight = Math.floor(parseInt(height, 10));
                    if ($textarea.height() != curratedHeight) {
                        $textarea.animate({
                            'height': curratedHeight + 'px',
                            'overflow': overflow
                        })
                    }
                }
                function update() {
                    var textareaContent = $textarea.val().replace(/&/g, '&amp;').replace(/  /g, '&nbsp;').replace(/<|>/g, '&gt;').replace(/\n/g, '<br />');
                    var twinContent = $twin.html();
                    if (textareaContent + '&nbsp;' != twinContent) {
                        $twin.html(textareaContent + '&nbsp;');
                        if (Math.abs($twin.height() + lineHeight - $textarea.height()) > 3) {
                            var goalheight = $twin.height() + lineHeight;
                            if (goalheight >= maxheight) {
                                setHeightAndOverflow(maxheight, 'auto')
                            } else if (goalheight <= minheight) {
                                setHeightAndOverflow(minheight, 'hidden')
                            } else {
                                setHeightAndOverflow(goalheight, 'hidden')
                            }
                        }
                    }
                }
                $textarea.css({
                    'overflow': 'hidden'
                });
                $textarea.keyup(function() {
                    update()
                });
                $textarea.live('input paste',
                function(e) {
                    setTimeout(update, 250)
                });
                update()
            })
        }
    })
})(jQuery);