DIV Scrolling (Stop At Content End). JavaScript.

Hello I have a website design. currently in XHTML and CSS. It consits of two major divs. a left and a right. left div has alot of content. right div has a fixed amout of content (~1000px) When a browser window shows all of the right div, i only want the left div to scroll. When a browser windows cuts of some of right div, i want both divs to scroll, but right div to stop scrolling when all content is shown. Id imagine this would be achieved using Javascript, and somehow making the right div stick to the bottom of the browser window? You can use jQuery if needed and is preferred. See attached image for screen shots of required result. Budget is extremely low, and needs to be completed ASAP. Cheapest with best credentials will win.