Jquery sticky menu

SH.stickyMenu = function() {
    var $window        = $(window),
      height          = $window.height(),
      width           = $window.width(),
      menu            = $('.c-sticky-menu'),
      mainmenuheight  = $('.c-main-header').height(),
      menuheight      = menu.height();
    
      var scrollTop = $window.scrollTop();

      if (scrollTop > (height - menuheight - mainmenuheight) - mainmenuheight ) {
        body.addClass('is-sticky');
      }else {
        body.removeClass('is-sticky');
      }

  }

$(window).on('scroll', function(){
  SH.stickyMenu();
})