Липкие блоки jquery?

    $(function() {
        var box = $('#messagelist'); // float-fixed block

        var top = box.offset().top - parseFloat(box.css('marginTop').replace(/auto/, 0));
        $(window).scroll(function(){
            var windowpos = $(window).scrollTop();
            if(windowpos < top) {
                box.css('position', 'static');
            } else {
                box.css('position', 'fixed');
                box.css('top', 0);
            }
        });
    });

$(document).ready(function(){
var obj = $('#sticky');
var offset = obj.offset();
var topOffset = offset.top;
var marginTop = obj.css("marginTop");

$(window).scroll(function() {
var scrollTop = $(window).scrollTop();

	if (scrollTop >= topOffset){

		obj.css({
			marginTop: 90,
			position: 'fixed',
		});
	}

	if (scrollTop < topOffset){

		obj.css({
			marginTop: 20,
			position: 'relative',
		});
	}
});
});