Duda.Ml1986@gmail.com,
вариант
<!DOCTYPE HTML>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<script src="http://code.jquery.com/jquery-latest.js"></script>
<style type="text/css">
li > ul {
display: none;
}
li{
list-style-type: none;
width: 100px;
}
a.plus, a.minus{
cursor: pointer;
}
a::before {
content: "▪ ";
margin-left: +2px;
}
.plus::before {
content: "+ ";
margin-left: 0px;
}
.minus::before {
content: "- ";
margin-left: 0px;
}
</style>
</head>
<body>
<ul id='nav'>
<li><a>link</a>
<ul class='sub'>
<li><a>link</a>
<ul class='subsub'>
<li><a>link</a></li>
<li></li>
<li></li>
<li></li>
</ul>
</li>
<li><a>link</a></li>
</ul>
</li>
<li><a>link</a></li>
</ul>
<script>
$(function () {
$('a:has(+ul)').click(function (e) {
$(this).toggleClass('plus minus')
e.preventDefault();
e.stopPropagation();
$('+ul', this).slideToggle();
}).addClass('plus');
})
</script>
</body>
</html>