nawigacja sticky nie dziala

Ćwiczę z 3 częścią kursu CSS Mirosława Zelenta i próbuję dodać "sticky" ale cos mi nie dziala. Nie wiem co zrobiłem źle. Plik jquery mam w folderze. Proszę o pomoc.

<!DOCTYPE HTML> 
<html lang='pl'> 
<head>
	<meta charset='utf-8'>
	<meta name='viewport' content='width=device-width, initial-scale=1, maximum-scale=1'>
	<title></title>
	<link rel='stylesheet' href='style.css'>
	<link rel="stylesheet" href="SlickNav/slicknav.css" />
<script src="SlickNav/jquery.slicknav.min.js"></script>

</head>
<body>

<div id="strona">
<nav id="nav">
<label for="show-menu" class="show-menu"><span>Menu</span><div class="lines"></div></label>
	<input type="checkbox" id="show-menu">
		<ul id="menu">
		<li><a href="#">Home</a></li>
		<li><a href="#">About</a></li>
		<li><a href="#">Portfolio</a></li>
		<li><a href="#">News</a></li>
		<li><a href="#">Contact</a></li>
	</ul>
</nav>
	
	
</div>




	
<script src="js/jquery-1.11.1.min.js"></script>
<script>

$(document).ready(function() {
   var stickyNavTop = $('#nav').offset().top;

   var stickyNav = function(){
   var scrollTop = $(window).scrollTop();

   if (scrollTop > stickyNavTop) { 
      $('#nav').addClass('sticky');
   } else {
      $('#nav').removeClass('sticky');
    }
   };

   stickyNav();

   $(window).scroll(function() {
      stickyNav();
   });
   });

</script>
</body>
</html>

*{
  margin:0;
  padding:0;
}
body {
	font-family: Helvetica, Arial, sans-serif;
  font-size:16px;
   
}

#strona{
    
    height: 2000px;
}

.sticky
{
    width: 100%;
    position: fixed;
    left: 0;
    top:0;
    z-index: 100;
}

#nav {
  display:block;
  width:100%;

line-height: 1.6em;
font-weight: 400;
width:100%;
text-align:center;
	position: relative;
  margin:0 auto;
}
/*Strip the ul of padding and list styling*/
#nav ul {
	list-style-type:none;
  margin: 0 auto;
  padding-left:0;
  text-align:center;
  width:100%;
  position: absolute;
  
    
    
    
    background: rgb(51,51,51); /* Old browsers */
	background: -moz-linear-gradient(top,  rgba(51,51,51,1) 0%, rgba(17,17,17,1) 100%); /* FF3.6+ */
	background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,rgba(51,51,51,1)), color-stop(100%,rgba(17,17,17,1))); /* Chrome,Safari4+ */
	background: -webkit-linear-gradient(top,  rgba(51,51,51,1) 0%,rgba(17,17,17,1) 100%); /* Chrome10+,Safari5.1+ */
	background: -o-linear-gradient(top,  rgba(51,51,51,1) 0%,rgba(17,17,17,1) 100%); /* Opera 11.10+ */
	background: -ms-linear-gradient(top,  rgba(51,51,51,1) 0%,rgba(17,17,17,1) 100%); /* IE10+ */
	background: linear-gradient(to bottom,  rgba(51,51,51,1) 0%,rgba(17,17,17,1) 100%); /* W3C */
	filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#333333', endColorstr='#111111',GradientType=0 ); /* IE6-9 */
}

/*Create a horizontal list with spacing*/
#nav li {
	display:inline-block;
	/*float: left;
	margin-right: 1px;*/
}

/*Style for menu links*/
#nav li a {
	display:block;
	min-width:140px;
	text-align: center;
	font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
	color: #fff;
  text-transform:uppercase;
	
	text-decoration: none;
  margin-left:-5px;
  padding: 10px 0;  
-webkit-transition: all 0.4s ease 0s;
-moz-transition: all 0.4s ease 0s;
-ms-transition: all 0.4s ease 0s;
-o-transition: all 0.4s ease 0s;
transition: all 0.4s ease 0s;
    
    
    background: rgb(51,51,51); /* Old browsers */
	background: -moz-linear-gradient(top,  rgba(51,51,51,1) 0%, rgba(17,17,17,1) 100%); /* FF3.6+ */
	background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,rgba(51,51,51,1)), color-stop(100%,rgba(17,17,17,1))); /* Chrome,Safari4+ */
	background: -webkit-linear-gradient(top,  rgba(51,51,51,1) 0%,rgba(17,17,17,1) 100%); /* Chrome10+,Safari5.1+ */
	background: -o-linear-gradient(top,  rgba(51,51,51,1) 0%,rgba(17,17,17,1) 100%); /* Opera 11.10+ */
	background: -ms-linear-gradient(top,  rgba(51,51,51,1) 0%,rgba(17,17,17,1) 100%); /* IE10+ */
	background: linear-gradient(to bottom,  rgba(51,51,51,1) 0%,rgba(17,17,17,1) 100%); /* W3C */
	filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#333333', endColorstr='#111111',GradientType=0 ); /* IE6-9 */
    
    
}

/*Hover state for top level links*/
#nav li:hover a {
	color: red;
  background-color:#ccddee;
}

/*Style for dropdown links*/
#nav li:hover ul a {
	background: #f3f3f3;
	color: #2f3036;
	height: 40px;
	line-height: 40px;
}

/*Hover state for dropdown links*/
#nav li:hover #nav ul a:hover {
	color: #4db3ff;
}

/*Hide dropdown links until they are needed*/
#nav li ul {
	display: none;
}

/*Make dropdown links vertical*/
#nav li ul li {
	display: block;
	float: none;
}

/*Prevent text wrapping*/
#nav li ul li a {
	width: auto;
	min-width: 100px;
	padding: 0 20px;
}


/*Style 'show menu' label button and hide it by default*/
#nav .show-menu {
	text-decoration: none;
	color: #fff;
	background: #8aa8bd;
	text-align: center;
	padding: 10px 15px;
	display: none;
  cursor: pointer;
  text-transform: uppercase;
}

#nav .show-menu span{
   padding-left: 35px;
}

/*Hide checkbox*/
#nav input[type=checkbox]{
    display: none;
}

/*Show menu when invisible checkbox is checked*/
#nav input[type=checkbox]:checked ~ #menu{
    display: block;
}

/*Responsive Styles*/

@media screen and (max-width : 800px){
  #nav .lines {
    border-bottom: 15px double #f8f8f8; 
    border-top: 5px solid #f8f8f8; 
    content:"";
    height: 5px; 
    width:20px;
    padding-right:15px;
  float: right;
}
	/*Make dropdown links appear inline*/
	#nav ul {
		position: static;
		display: none;
	}
	/*Create vertical spacing*/
	#nav li {
		margin-bottom: 1px;
	}
	/*Make all menu links full width*/
	#nav ul li, #nav li a {
		width: 100%;
	}
	/*Display 'show menu' link*/
	#nav .show-menu {
		display:block;
	}
}