You should start using jQuery or some other js lib.  It's way easier than js, and you can use it as a shorthand for most js instead of actually long, drawn out js.
Simply put <script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script> (or whatever the latest google cdn is https://developers.google.com/speed/libraries/devguide#jquery) in your <head>.
Then, inside your event code (much easier if you use jQuery: $.click() for buttons, $.change() for checkboxes, selects, radios...), put the code from your second link looking more like 
$('#theIDofTheButtonThatTriggersThisAnimation').click(function(){
    $('#theIDofTheElementYouWantToSmoothlyScroll').animate({
        scrollTop: 0
    }, 2000);
});
However, if you're trying to do animations, I recommend you look into some basic css properties like position:absolute and position:relative to keep from going crazy.
I'm still not quite sure what's going on in your code because it's very non-standard relative to how things are done now with css & jQuery.  I'd break it down into something simple to learn the general concept.
For your example, you should build off of my animation example, how I learned: https://stackoverflow.com/a/12906254/1382306
I think you're trying to move your text up and down based upon a $.click().  In the fiddle in my answer, it slides left and right.  You can easily reformat up and down by using the css top property instead of left.
Once you figure out how to move the entire div up and down, you can make a relative container to hold all of the content absolute divs and manipulate all content divs with a loop by setting their tops.  Here's a quick primer on absolute in relative: http://css-tricks.com/absolute-positioning-inside-relative-positioning/
All of my animations have relative containers and absolute content.  It's how I made a custom gridview plugin that can instantly zip through an entire database.
Also, there really is no overuse of divs when it comes to animating.  Trying to make 1 div do everything is a nightmare.
Try to see if you can reformat my fiddle into a vertical slide out.  Once you've done that, research absolute in relative a little.  If you have any more problems, just ask another question.
Change your thinking to these philosophies, and you'll start flying through this type of coding.