Change Progress Bar Value based on Scrolling

Question

I would like to be able to make my progress bar increase, based on how far I've scrolled and how much is left.

I've tried this: jsFiddle and it doesn't seem to work, I based my script off someone's script that made a block move horizontally based on scroll %.

My code:

<progress id="progressbar" value="0" max="100"></progress>
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JS:

$(document).ready(function () {
    $(window).scroll(function () {
        var s = $(this).scrollTop(),
            d = $(document).height(),
            scrollPercent = (s / d);
        var position = (scrollPercent);
        $("#progressbar").progressbar('value', position);
    });
});

Answer 1

The logic is like this

totalValue  = (documentHeight - windowHeight);
currntValue = scrolledValue;
percentage =  (currntValue/ totalValue  ) * 100

http://jsfiddle.net/PvVdq/71/

   $(document).ready(function () {
    $(window).scroll(function () {
        var s = $(this).scrollTop(),
            d = $(document).height()-$(window).height(),
            scrollPercent = (s / d)*100;       
        $("#progressbar").attr('value', scrollPercent);
     });
 });

Answer 2

Working DEMO

Try this

$(window).scroll(function () {
  var s = $(window).scrollTop(),
        d = $(document).height(),
        c = $(window).height();
        scrollPercent = (s / (d-c)) * 100;
        var position = scrollPercent;

   $("#progressbar").attr('value', position);

});

Hope this helps, Thank you