(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 * 3,
        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.css({
              '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);