<html>
<head>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>
</head>
<body>
<div id=myCondoms>
<input type=checkbox name=activator value=1 />
<select name=condoms1 disabled='disabled'><option>contex</option><option>visit</option></select>
</div>
<script>
var select = $('div#myCondoms').find('select');
$('input[name=activator]').toggle(function(){
select.attr('disabled', '');
},function(){
select.attr('disabled', 'disabled');
});
</script>
</body>
</html>