Plaats de stylesheet in de head-sectie van jouw pagina, en de html-code in de body-sectie van de pagina. In broncode kan je de class "inline regels_x" vinden. De x staat voor het aantal elementen in de <li>. Dus als er vijf menu-elementen zijn vul je bij de class: class="inner regels_5" in. Er wordt overigens nog gesleuteld aan deze procedure, maar zoals hij hier staat is hij al uitstekend te gebruiken.
<style type="text/css">
.slide_down{
padding:0;
margin:0;
list-style:none;
font-size:13px;
height:40px;
float:left;
position:relative;
z-index:100;
margin-right:1px;
margin-bottom:30px}
.eerste{
margin-left:30px}
.slide_down li{float:left;
position:relative}
.slide_down li.sluiten{
width:30px;
height:40px;
position:absolute;
right:0;
top:0;
z-index:-1}
.slide_down li.sluiten a{
display:block;
width:30px;
height:40px;
background:url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAB4AAAAoBAMAAAAbPVchAAAAHlBMVEUAAAD////E1cS/0b+hv6F/pIBrlWxjj2RhjmNMb01Fdog+AAAAAXRSTlMAQObYZgAAAEFJREFUKJFj6EAGSQwMKPwOBTR+Ahq/GY3fyjAFVWCo8hsrUPmC4ij8RkHBCmS+oCBUAYQPlBYUHFD3k83voC8fAC25OR10zOa9AAAAAElFTkSuQmCC')}
.slide_down li.sluiten a b{
position:absolute;
left:-9999px}
.slide_down li a.lijst_top_a{
text-decoration:none;
white-space:nowrap;
display:block;
cursor:pointer;
height:40px;
line-height:40px;
float:left;
font-weight:normal;
color:#fff;
background:url('data:image/png;base64,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') no-repeat top left;
padding-left:10px;
padding-right:10px;
padding-top:0;
padding-bottom:0}
.slide_down li div.pijltje{
float:left;
cursor:pointer;
width:30px;
height:40px;
font-weight:normal;
background:url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAK4AAAGQBAMAAADFJUa0AAAALVBMVEUAAAD////x9fHw9PDZ49nE1cXE1cSnwKemv6ehv6F/pIB0m3VrlWxhjmNMb01UKt9kAAAAAXRSTlMAQObYZgAAAQdJREFUeJzt0LFNw2AUhdErIaUJDQNkhGySggEomAOJBVgEGu/gJuldWbL0D8AWuDCFqf8nFOl83WuOrl6Sj9a7r6xdurOt3ZJDAdvaax5L3DHnEnfOUOIu6SV9708ul8vdu9PTWoHbVvZU4U7b3O7/3eZ2d6dW4/7G5XLv0P0Tl8vlcrlcLpfL5XK5XC6Xy+VyuVwul8vlcrlcLpfL5XK5XC6Xy+VyuVwul8vlcrlcLpfL5XK5XC6Xy+VyuVwul8vlcrlcLpfL5XK5XC6Xy+VyuVwul8vlcrlcLpfL5XK5XC6Xy+VyuVwul/sv7lDCLnkvceccS9wxDyXuc/JSwF6z9tad/Ux+ACenRehZKWWmAAAAAElFTkSuQmCC') no-repeat top right}
.slide_down li.geen_sub a{
padding:0 0 0 10px}
.slide_down li.geen_sub b{
display:block;
width:10px;
height:40px;
float:left;
background:url('data:image/png;base64,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') no-repeat top right}
.slide_down div.inner{
position:absolute;
left:0;
top:40px;
height:0;
width:174px;
overflow:hidden;
-webkit-transition: 0.4s ease-in-out;
-moz-transition: 0.4s ease-in-out;
-o-transition: 0.4s ease-in-out;
transition: 0.4s ease-in-out}
.slide_down li div.pijltje:hover div.regels_1{height:32px;}
.slide_down li div.pijltje:hover div.regels_2{height:52px;}
.slide_down li div.pijltje:hover div.regels_3{height:72px;}
.slide_down li div.pijltje:hover div.regels_4{height:92px;}
.slide_down li div.pijltje:hover div.regels_5{height:112px;}
.slide_down li div.pijltje:hover div.regels_6{height:132px;}
.slide_down li div.pijltje:hover div ul{top:0;}
/* IE6 */
.slide_down table{
border-collapse:collapse;
padding:0;
margin:0 -20px -1px 0;
position:absolute;left:0; top:0}
.slide_down li a.sub-a{display:block; float:left; width:30px; height:40px;}
.slide_down li a.sub-a:hover{direction:ltr;}
.slide_down li a.sub-a:hover div.regels_1{height:32px;}
.slide_down li a.sub-a:hover div.regels_2{height:52px;}
.slide_down li a.sub-a:hover div.regels_3{height:72px;}
.slide_down li a.sub-a:hover div.regels_4{height:92px;}
.slide_down li a.sub-a:hover div.regels_5{height:112px;}
.slide_down li a.sub-a:hover div.regels_6{height:132px;}
.slide_down li a.sub-a:hover ul{top:0;}
/* einde IE6 */
.slide_down li ul{
margin:0;
background:url('data:image/png;base64,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') no-repeat bottom left;
width:0;
position:absolute;
width:170px;
-webkit-transition: 0.4s ease-in-out;
-moz-transition: 0.4s ease-in-out;
-o-transition: 0.4s ease-in-out;
transition: 0.4s ease-in-out; list-style-type:none; padding-left:2px; padding-right:2px; padding-top:2px; padding-bottom:10px}
.slide_down li div.regels_1 ul{top:-32px;}
.slide_down li div.regels_2 ul{top:-52px;}
.slide_down li div.regels_3 ul{top:-72px;}
.slide_down li div.regels_4 ul{top:-92px;}
.slide_down li div.regels_5 ul{top:-112px;}
.slide_down li div.regels_6 ul{top:-132px;}
.slide_down li ul li{
float:none;
width:170px;
margin:0;
height:20px}
.slide_down li ul li a{
display:block;
text-decoration:none;
height:20px;
line-height:20px;
padding:0 5px;
background-image:none;
color:#fff;
font-size:12px;
width:160px}
.slide_down li ul li a:hover{background:#618EA4;}
</style>
<style media="only screen and (max-device-width:768px)" type="text/css">
.slide_down a.tik {display:block; width:30px; height:40px; margin-bottom:-40px;}
.slide_down a.tik:hover + div.regels_1 {height:32px;}
.slide_down a.tik:hover + div.regels_2 {height:52px;}
.slide_down a.tik:hover + div.regels_3 {height:72px;}
.slide_down a.tik:hover + div.regels_4 {height:92px;}
.slide_down a.tik:hover + div.regels_5 {height:112px;}
.slide_down a.tik:hover + div.regels_6 {height:132px;}
.slide_down a.tik:hover + div ul {top:0;}
.slide_down li.lijst_boven:hover + li.sluiten {z-index:100;}
</style>
<ul class="slide_down eerste">
<li class="geen_sub"><a class="lijst_top_a" href="http://kompoos.nl/css/text-effects/slide-down-menu.html">Eerste</a><b></b></li>
</ul>
<ul class="slide_down">
<li class="lijst_boven"><a class="lijst_top_a" href="http://kompoos.nl/css/text-effects/slide-down-menu.html">Tweede</a>
<div class="pijltje"><a class="tik" href="http://kompoos.nl/css/text-effects/slide-down-menu.html"></a>
<div class="inner regels_5">
<ul>
<li><a href="http://kompoos.nl/css/text-effects/slide-down-menu.html">een slide down</a></li>
<li><a href="http://kompoos.nl/css/text-effects/slide-down-menu.html">menu met horizontale</a></li>
<li><a href="http://kompoos.nl/css/text-effects/slide-down-menu.html">tabs en geheel</a></li>
<li><a href="http://kompoos.nl/css/text-effects/slide-down-menu.html">cross browser</a></li>
<li><a href="http://kompoos.nl/css/text-effects/slide-down-menu.html">ook voor mobiel</a></li>
</ul>
</div>
</div>
</li>
<li class="sluiten"><a href="http://kompoos.nl/css/text-effects/slide-down-menu.html"><b>Sluiten</b></a></li>
</ul>
<ul class="slide_down">
<li class="lijst_boven"><a class="lijst_top_a" href="http://kompoos.nl/css/text-effects/slide-down-menu.html">Derde</a>
<div class="pijltje"><a class="tik" href="http://kompoos.nl/css/text-effects/slide-down-menu.html"></a>
<!--[if lte IE 6]><a class="sub-a" href="http://kompoos.nl/css/text-effects/slide-down-menu.html"><table><tr><td>
<![endif]-->
<div class="inner regels_3">
<ul>
<li><a href="http://kompoos.nl/css/text-effects/slide-down-menu.html">cross browser</a></li>
<li><a href="http://kompoos.nl/css/text-effects/slide-down-menu.html">menu's werken</a></li>
<li><a href="http://kompoos.nl/css/text-effects/slide-down-menu.html">altijd en overal</a></li>
</ul>
</div>
</div>
</li>
<li class="sluiten"><a href="http://kompoos.nl/css/text-effects/slide-down-menu.html"><b>Sluiten</b></a></li>
</ul>
<ul class="slide_down">
<li class="lijst_boven"><a class="lijst_top_a" href="http://kompoos.nl/css/text-effects/slide-down-menu.html">Vierde</a>
<div class="pijltje"><a class="tik" href="http://kompoos.nl/css/text-effects/slide-down-menu.html"></a>
<div class="inner regels_6">
<ul>
<li><a href="http://kompoos.nl/css/text-effects/slide-down-menu.html">Je kan zelf</a></li>
<li><a href="http://kompoos.nl/css/text-effects/slide-down-menu.html">de CSS code</a></li>
<li><a href="http://kompoos.nl/css/text-effects/slide-down-menu.html">aanpassen</a></li>
<li><a href="http://kompoos.nl/css/text-effects/slide-down-menu.html">op alle mogelijke</a></li>
<li><a href="http://kompoos.nl/css/text-effects/slide-down-menu.html">manieren die</a></li>
<li><a href="http://kompoos.nl/css/text-effects/slide-down-menu.html">je maar wilt</a></li>
</ul>
</div>
</div>
</li>
<li class="sluiten"><a href="http://kompoos.nl/css/text-effects/slide-down-menu.html"><b>Sluiten</b></a></li>
</ul>
<ul class="slide_down">
<li class="lijst_boven"><a class="lijst_top_a" href="http://kompoos.nl/css/text-effects/slide-down-menu.html">Vijfde</a>
<div class="pijltje"><a class="tik" href="http://kompoos.nl/css/text-effects/slide-down-menu.html"></a>
<div class="inner regels_3">
<ul>
<li><a href="http://kompoos.nl/css/text-effects/slide-down-menu.html">Alleen minder</a></li>
<li><a href="http://kompoos.nl/css/text-effects/slide-down-menu.html">dan IE6 wordt niet</a></li>
<li><a href="http://kompoos.nl/css/text-effects/slide-down-menu.html">meer ondersteund</a></li>
</ul>
</div>
</div>
</li>
<li class="sluiten"><a href="http://kompoos.nl/css/text-effects/slide-down-menu.html"><b>Sluiten</b></a></li>
</ul>
<div style="clear:both;"></div>