The HTML & CSS Code
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>HTML Test</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<style type="text/css">
.nav ul {list-style:none; margin:0; padding:0}
.nav li {float:left; width:100px; background-color:#444444; text-align:center;
border-right:1px solid white; position:relative;
height:30px; line-height:30px;}
.nav li ul li {float:none; width:150px; text-align:left; padding-left:5px;
border-top:1px solid white;}
.nav a {text-decoration:none; color:white;}
.nav li ul {position:absolute; top:30px; left:0; visibility:hidden;}
.nav li:hover ul {visibility:visible;}
.nav li:hover {background-color:maroon;}
.content {clear:both;}
</style>
</head>
<body>
<h1>Heading Section</h1>
<div class="nav">
<ul>
<li>
<a href="home.html">Home</a>
</li>
<li>
<a href="photos.html">Photos</a>
<ul>
<li><a href="zoo.html">Zoo</a></li>
<li><a href="lake.html">At the Lake</a></li>
<li><a href="sunset.html">Sunset</a></li>
</ul>
</li>
<li>
<a href="contact.html">Contact</a>
</li>
</ul>
</div>
<h2 class="content">This is the content section.</h2>
</body>
</html>