Shrinking navigation bar when scrolling down (bootstrap3)

Question

I would like to build a navigation-bar effect like it is on http://dootrix.com/ on my page (after scrolling down the bar getting smaller and the logo changes). Im using boot

Answer 1

toggleClass works too:

$(window).on("scroll", function() {
    $("nav").toggleClass("shrink", $(this).scrollTop() > 50)
});