Floating footer jquery plugin? (NOT the commonly asked "how to make a footer stick to the bottom of the page")

NOTE This question is NOT the commonly asked "how to make a footer stick to the bottom of the page"

Is there a jquery plugin that floats a footer above all other elements if you are not scrolled to it?

This is what my layout looks like:

nav bar

picture

footer 1

text

footer 2

So I want something that will float the footer 1 to the bottom of the viewable screen while you are scrolled to a point above the fo开发者_高级运维oter 1 (if you are looking at the nav bar and picture, and footer 1 is normally out of view, I want it to float to the bottom), however, after you scroll past the footer 1, it should go back to normal.

I might have written a plugin which could at least give you an idea on how to accomplish this, check it out at github.