Border using a Image

I have what might be a unusual problem.

Go here...this is a test page: http://sautters.net/sautters2/gc-test/
(This page is not i menu, but is available, so you can look at other pages)


I need to create a border (the green line, preferably) using a image.
It needs to be expandable to adjust for differring heights of each page. (preferably)

That is my first issue. My second issue is that different page will be using different borders.

I am at a complete loss to due this, I can not even seem to create a single border, aside from the solid color border.

This needs to be simple, as i can modify (edit) current CSS, PHP, etc, but do not know enuf to create/insert any of the above.

I hope someone can help me.

Thanks for your help.