nella pagina Html o Xhtml
<ul>
<li><a class="button" href="#nogo" title="" >link uno</a></li>
<li><a class="button" href="#nogo" title="" >link due</a></li>
<li><a class="button" href="#nogo" title="" >link tre</a></li>
<li><a class="button" href="#nogo" title="" >link quattro</a></li>
<li><a class="button" href="#nogo" title="" >link cinque</a></li>
</ul>
</div>
nel css
#menu {position: relative; margin-top: 20px; left: 5px; display: block; width: 350px;}
#menu a.button, #menu a.button:visited {display: block; width: 150px; height: 30px; background: url(/immagini buttons.gif); background-position: top left; background-color: transparent; text-align: center; color: #000; line-height: 28px; text-decoration: none; font-family: arial, sans-serif; font-weight: bold; margin-top: 5px;}
#menu a.button:hover {background-position: 0 -30px; line-height: 31px; overflow: hidden;}
#menu a.button:active {background-position: 0 -60px;}