Sticky js script found on http://www.9news.com.au/

fixed-block.js

(function () {
    define('redesign/ninemsn/portal/news/stickyElementController',['jquery', 'redesign/ninemsn/portal/news/helper'], function ($, helper) {

        var bufferY = 56; // Offset for fixed positioning

        var windowTop,
            startY,
            blockY,
            stopY,
            offset;

        // Methods
        var prepareFixedElements,
            updateFixedElements,
            applyStopped,
            applyFixed,
            applyDefault,
            updateBufferHeight,
            resetFixedElements,
            notDesktop;

        prepareFixedElements = function () {
            
            $('.js-fixed-block').each(function () {
                $(this).wrap('<div class="js-wrapper fixed-block-wrapper" style="position: relative"></div>');
                applyDefault($(this));
            });
        };

        updateFixedElements = function () {

            var $stopper;
            
            if ($(window).width() < 900) {
                resetFixedElements();
            } else {

                $('.js-fixed-block').each(function () {

                    if ($(this).hasClass('fixed-disabled')) {
                        applyDefault($(this));
                        $(this).removeClass('fixed-disabled');
                    }

                    windowTop = $(window).scrollTop();
                    startY = $(this).parent().offset().top;
                    blockY = $(this).outerHeight();
                    $stopper = $($(this).attr('data-stopper'));

                    stopY = 9e9;

                    if ($stopper.length) {
                        stopY = ($stopper.offset().top - blockY - bufferY);
                    }
                    
                    if (windowTop > stopY) {
                        offset = (stopY - $(this).parent().offset().top + bufferY);
                        applyStopped($(this), offset);
                    } else if (windowTop > (startY - bufferY)) {
                        applyFixed($(this));
                    } else {
                        applyDefault($(this));
                    }

                });

            }
        };

        applyStopped = function (element, offset) {
                
            var y = element.outerHeight();

            if (offset < 0) offset = 0;

            element.css({
                'position': 'absolute',
                'top': offset + 'px'
            });

            updateBufferHeight(element.parent(), y);
        };

        applyFixed = function (element) {

            var y = element.outerHeight();

            element.css({
                'position': 'fixed',
                'top': bufferY + 'px',
                'width': element.parent().width() + 'px',
                'height': 'auto'
            });

            updateBufferHeight(element.parent(), y);
        };

        applyDefault = function (element) {

            // Default is the original block inside a wrapper to preserve
            // the space when the fixed block is removed from the flow.

            var y = element.outerHeight();
            var x = element.outerWidth();
            
            element.css({
                'position': 'absolute',
                'width': x + 'px',
                'top': 0
            });
            
            updateBufferHeight(element.parent(), y);
        };

        updateBufferHeight = function (element, y) {
            element.css({
                'height': y + 'px',
                'position': 'relative'
            });
        };

        resetFixedElements = function () {
            $('.js-fixed-block, .js-wrapper').attr('style', '');
            $('.js-wrapper, .js-fixed-block').addClass('fixed-disabled');
        };

        notDesktop = function () {
            return navigator.userAgent.match(/Android|BlackBerry|iPhone|iPad|iPod|Opera Mini|IEMobile/i);
        };

        return {
            init: function () {
                // Disabled for touch devices using user agent, as checking for touch events is unreliably buggy for windows 8 + chrome
                if (notDesktop()) {
                    return false;
                }

                // We need to wait until the assets are loaded to determine the rendered height.
                prepareFixedElements();
                updateFixedElements();

                // We must listen to resize for responsiveness...
                $(window).resize(function () {
                    updateFixedElements();
                });

                $(window).scroll(function () {
                    updateFixedElements();
                });
                
                // check for loaded ads
                $('body').on('ad.loaded', function () {
                    updateFixedElements();
                });
            }
        };
    });
}).call(this);