F.eks. kan man gøre sådan:
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"
http://www.w3.org/TR/html4/loose.dtd"><html>
<head>
<title>Tomt dokument</title>
<meta name="keywords" content="søgeord adskilt af komma">
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<style type="text/css">
html,body{height:100%;margin:0px;border:0px;padding:0px;font-family:tahoma,verdana,arial,sans-serif;font-size:small;}
</style>
<script language="javascript" type="text/javascript">
var models = new Array();
models[models.length] = ["234","235","224","24","4","5"];
models[models.length] = ["245","247","C23","Q13","645"];
models[models.length] = ["323","626","929"];
function showModels(elm){
elm.form.text.style.display = 'none';
var sel = elm.form.select2;
if(elm.selectedIndex==0){
sel.style.display = 'none';
}else{
sel.length = 1;
var arrNum = elm.selectedIndex-1;
for(i=0;models[arrNum].length>i;i++){
sel.options[sel.length] = new Option(models[arrNum][i]);
sel.style.display = 'inline';
}
}
}
</script>
</head>
<body>
<form id="minForm" name="minForm">
Vælg mærke:<br>
<select name="minSelect" id="minSelect" onchange="showModels(this);">
<option value="">-- Vælg her --<br>
<option value="1">BMW<br>
<option value="2">Volvo<br>
<option value="3">Mazda<br>
</select>
<br>Vælg model:<br>
<select name="select2" id="select2" style="display:none;" onchange="this.form.text.style.display=this.selectedIndex>0?'inline':'none';">
<option value="">-- Vælg her --<br>
</select>
<br>Supplerende tekst:
<input type="text" name="text" style="display:none;">
<br>
<input type="submit" value="send">
</form>
</body>
</html>