<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=iso-8859-1" />
<meta name="author" content="" />
<script type="text/javascript">
function run(){
var cb = document.getElementById("cb");
if(document.getElementById("cekbox").checked == true){
cb.disabled = true;
}else{
cb.disabled = false;
}
}
</script>
<title>Enable/Disable ComboBox</title>
</head>
<body>
<input type="checkbox" name="a" id="cekbox" onclick="run();" />Disable Checkbox<br /><br />
<select id="cb" size="1">
<option>a</option>
<option>b</option>
</select>
</body>
</html>