Javascript - jquery help please

$(document).ready(function(){
	var $nav = $(".top-normal .nav-normal")
	var $win = $(window)
	$nav.on('scroll',function(){
		var top = $win.scrollTop()
		alert(top)
		if (top > 100){
			$nav.css("backgroundColor","red")
		}
	});
});

Does anyone know why the code above doesnt work? I have linked correctly the javascript file in html and they are located on the same folder. (btw the problem isnt with linking) any help??

I think you are missing semi colons on a lot of things.