var wind = window;
$(document).on("scroll", function(e){
	var sect = $(this).find('.sect');
	sect.each(function(i){
		if(wind.scrollY >= sect[i].offsetTop - 100 && wind.scrollY <= sect[i].offsetTop + 50){
			var ths = $(this)
			var id = ths.attr('id');
			var link = $('.my_mnu').find('.link');
			link.each(function(){
				var link_ths = $(this)
				var href = $(this).attr('href');
				var string = href.substr(1, href.length);
				if(id == string){
					link.removeClass('active');
					link_ths.addClass('active');
				}
			})
		}
	})
})