Use float with a list of hyperlinks to create a horizontal menu.
Code
<html>
<head>
<style type="text/css">
ul
{
float:left;
width:100%;
padding:0;
margin:0;
list-style-type:none;
}
li {display:inline}
a
{
float:left;
width:6em;
text-decoration:none;
color:white;
background-color:purple;
padding:0.2em 0.6em;
border-right:1px solid white;
}
a:hover {background-color:#ff3300}
</style>
</head>
<body>
<ul>
<li><a href="#">Link one</a></li>
<li><a href="#">Link two</a></li>
<li><a href="#">Link three</a></li>
<li><a href="#">Link four</a></li>
</ul>
<p>
In the example above, we let the ul element and the a element float to the left.
The li elements will be displayed as inline elements (no line break before or after the element). This forces the list to be on one line.
The ul element has a width of 100% and each hyperlink in the list has a width of 6em (6 times the size of the current font).
We add some colors and borders to make it more fancy.
</p>
</body>
</html>