jquery.stickyToolbar.js

(function($){
  $.fn.sticky = function () {
    var toolbar = $(this);
    var wrapper = $(this).wrap($('<div />', { id : toolbar.attr('id') + '-wrapper'})).parent();
    $(this).width(wrapper.width());
    wrapper.height($(this).outerHeight());

    $(window).bind('scroll resize', function () {
      toolbar.toggleClass('follow', !$.fn.sticky.isScrolledIntoView(wrapper));
    });
    $(window).resize();
  };

  $.fn.extend($.fn.sticky, {
    isScrolledIntoView: function (elem, bottom) {
      var docViewTop = $(window).scrollTop();
      var docViewBottom = docViewTop + $(window).height();
  
      var elemTop = elem.offset().top;
      var elemBottom = elemTop + elem.height();
  
      return ((elemBottom >= docViewTop) && (elemBottom <= docViewBottom));
    }
  });
})(jQuery);