Mega Code Archive
Change the size of a dropdown list (ComboBox)
<![CDATA[
<html>
<head>
<script type="text/javascript">
function formAction(){
var x=document.getElementById("mySelect")
x.size="3"
}
</script>
</head>
<body>
<form>
<select id="mySelect">
<option>1</option>
<option>2</option>
<option>3</option>
<option>4</option>
</select>
<input type="button" onclick="formAction()" value="Change size of list">
</form>
</body>
</html>
]]>