Parallaxing bg image relative to parent container
I'm using this jquery plugin to create a background parallax effect.
http://www.jsplugins.com/Scripts/Plugins/View/Jquery-Background-Parallax/
You can find a demo here that I've been playing with a little bit.
http://204.250.154.51/dev/parallax/index.html
I can get the plugin to work at a basic level no problem, scrolling the contents within an element parallaxes the background as it should. What I'm trying to figure out how to do, is the parallax the bg images for each of the 4 divs relative to the scroll bar on the parent element. So the end result is, you scroll the entire page, and all 4 divs parallax simultaneously.
EDIT: I'm still just playing around here, and I'm not completely sure that this plugin is actually capable of this. If not, would anybody be aware of another plugin, or library, that could do this for me?