I wouldn't know about this, depends on what system you are using. I usually use Subdreamer CMS since that system is really easy to use and make templates for. But a lot of people use Wordpress or Joomla which I don't really know much about.

Sure it's pretty basic really. You just divide the page up into 3 horizontal sections. You have your header, then your content/middle area then your base/bottom area. You then divide these sections into 3 vertical sections. So you end up with a left, middle and right areas in them.

Then all you need to do is create images which have that white border in them. For the header and base images, you have this as a single/non-repeating image. For the middle section though, you make the left and right image repeat vertically. So when the page expands, the image repeats itself down.

In other words, the header and base images are single images which don't repeat. The middle content area you make the images repeat so you can have that as an expandable content area.

Hope that helps?