Valedus,
<!DOCTYPE html>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<script src="http://code.jquery.com/jquery-1.9.1.js">
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<style type="text/css">
.topic ul{
display: none;
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.active > ul{
display: block;
}
</style>
<script>
$(function ()
{
$(".topic ul").prev("a").click(function(event){
$('.active').removeClass('active');
$(this).parent().addClass('active');
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</head>
<body>
<div class="photo">
<ul class="topic">
<!--тут-->
<li class="active">
<a class="set" href="#Portraits">Portraits</a>
<ul>
<li>
<a href="http://www.cssplay.co.uk/menu/lbox/landscape1.jpg"><img src=
"http://www.cssplay.co.uk/menu/lbox/landscape1a.jpg" alt="" title=""></a>
</li>
<li>
<a href="http://www.cssplay.co.uk/menu/lbox/landscape2.jpg"><img src=
"http://www.cssplay.co.uk/menu/lbox/landscape2a.jpg" alt="" title=""></a>
</li>
</ul>
</li><!--тут-->
<li>
<a class="set" href="#Landscapes">Landscapes</a>
<ul>
<li>
<a href="http://www.cssplay.co.uk/menu/lbox/landscape3.jpg"><img src=
"http://www.cssplay.co.uk/menu/lbox/landscape3a.jpg" alt="" title=""></a>
</li>
<li>
<a href="http://www.cssplay.co.uk/menu/lbox/landscape4.jpg"><img src=
"http://www.cssplay.co.uk/menu/lbox/landscape4a.jpg" alt="" title=""></a>
</li>
</ul>
</li>
</ul>
</div>
</body>
</html>