Background Frame Change (PHP) (WALLPAPER)

We require someone with PHP Knowledge to fix out website frames, Currently the background image cover's all the space outside the frame but instead we would like Left background and Right background sides. We would like to be able to upload the changable banners in our administrator area in the backend of the website. It has to be able to be changed Per Page. Example : Home page - Left side background Right side background SHow Page - Left Side background Right side background We also have a Backend CMS It only needs a few lines on the core template and it should work fine. I have attached a screen shot of our website so I can show you what i mean. Bidders , need this work finished today.