Well, you can do it with 3 divs.
<div class="bg"><div class="top"><div class="bot">text here</div></div></div>
bg
would have css like
background: url(path/to/repeated/background.gif) repeat-y;
Where the background spans the entire width of the div, since it's constant. That will tile both your left and right sides.
And then for the top and bottom just use images with no-repeat top left;
and no-repeat bottom left
. They would each have 2 corners plus all the imagey goodness inbetween.
Hopefully you can fill in the details from that if you have a good enough understanding of CSS.