Sticky Header after scrolling down

Question

I saw this sticky header on this website: http://dunked.com/ (no longer active, view archived site)

When you scroll down the sticky header comes down from t

Answer 1

This was not working for me in Firefox.

We added a conditional based on whether the code places the overflow at the html level. See Animate scrollTop not working in firefox.

  var $header = $("#header #menu-wrap-left"),
  $clone = $header.before($header.clone().addClass("clone"));

  $(window).on("scroll", function() {
    var fromTop = Array(); 
    fromTop["body"] = $("body").scrollTop();
    fromTop["html"] = $("body,html").scrollTop();

if (fromTop["body"]) 
    $('body').toggleClass("down", (fromTop["body"] > 650));

if (fromTop["html"]) 
    $('body,html').toggleClass("down", (fromTop["html"] > 650));

  });