Question

Can someone help with this jsfiddle?

http://jsfiddle.net/4Ns44/

Intended purpose: when the page is scrolled down, link expands in the view port, This works good. But as we scroll up, I would like the expand window to stop where it started. ie, below the header div. Right now, the position:fixed is causing it to remain at top even after the header div becomes visible.

some help with position:fixed

Answer 1

If I understand what you’re trying to do, I think you want to check for when scrollTop is less than the original position of #expand. In particular:

var minY = $('#header').height();

In the scroll handler:

// this will reset to the original position
if (top < minY) {
    $expand.css({position: "absolute", top: ''});
}

Resulting in this: http://jsfiddle.net/4Ns44/3/

var minY = $('#header').height();
var $expand = $("#expand");

$(window).scroll(function () {

    var top = $(window).scrollTop();

    if($expand.css("position") === "fixed") {

        if(top > expandY) {
            $expand.css({position: "absolute", top: expandY});
        } else if (top < minY) {
            $expand.css({position: "absolute", top: ''});
        }
    }
    else {
        if (top < minY) {
            $expand.css({position: "absolute", top: ''});
        } else if(top < expandY) {
            $expand.css({position: "fixed", top: 0});
        }
    }
});

This is if I understand what you’re trying to do…