JQuery :: Making Multiple Divs Appear Or Disappear When Diff Sections Of Site Are Scrolled To?

I am trying to create a fixed crest at the top of my site that changes depending on where the viewer of the site scrolls to.

I found the following script/plugin on StackOverflow that works well for making one element fade in and fade out.

PART ONE:

function isScrolledIntoView(elem) {
var docViewTop = $(window).scrollTop();
var docViewBottom = docViewTop + $(window).height();
var elemTop = $(elem).offset().top;

[Code].....

I then duplicated part two and changed the variables to make a different div appear in this position depending on where the viewer was in the site but it did not work past the first transition. see the following link to get a better idea what I am trying to achieve.

[URL]

Is there any way I can adjust the script to make it work with multiple transitions?