Create an irregular border

I am trying to create an irregular border around a div, the div will contain text. I am currently using two different images and making them background on the top and bottom of the div. This method works out pretty well but the problem is the div can grow, i.e. it can have variable width and height depending on its content. So, in this case using images as background to achieve this effect is no longer viable.

Is there any way to create an irregular border using CSS and javascript? Obviously, the border should accommodate variable width and height.

I am trying to achieve something like this, but on all sides.