Have a look at this:

http://www.scruffian.com/pinkscales/

currently the sides are set to a height which is 1000 pixels high, but as you can see if the content in the middle gets larger than 1000 pixels the sides don't carry on down. I have tried setting the css to height:100% but that doesn't work. What can I do to make the right and left layers continue down with the center layer?

Thanks
Ben