CSS:

/* Menu */

#menu {
	float: right;
	width: 550px;
	height: 127px;
}

#menu ul {
	float: right;
	margin: 0;
	list-style: none;
	line-height: normal;
}

#menu li {
	display: block;
	float: left;
	background: url(images/img02.gif) repeat-x left bottom;
}

#menu a {
	display: block;
	float: left;
	height: 45px;
	margin-right: 1px;
	padding: 40px 12px 0px 12px;
	text-decoration: none;
	text-align: center;
	text-transform: none;
	font-size: 18px;
	color: #713652;
}

#menu a:hover {
	background: #AA0E0E;
	border-bottom: 6px solid #c18e0f;
	color: #FFFFFF;
}

#menu .current_page_item a { 
	background: #AA0E0E;
	border-bottom: 6px solid #c18e0f;
	color: #FFFFFF;
}

#menu .first {

}

HTML:

<div id="menu">
		<ul>
			<li class="current_page_item"><a href="index.html" class="first">Home</a></li>
			<li><a href="voorstellen.html">Voorstellen</a></li>
            <li><a href="mogelijkheden.html">Mogelijkheden</a></li>
			<li><a href="contact.html">Contact</a></li>
		</ul>
	</div>