[cmd]

<form id="myform">
	<input id="myinput">

	<select id="myselect">
		<option value="1">1</option>
		<option value="2">2</option>
		<option value="3">3</option>
		<option value="4">4</option>
		<option value="5">5</option>
	</select>

</form>
 <script src="http://code.jquery.com/jquery-latest.js"></script>
<script>
$('#myselect option[value="2"], #myselect option[value="4"]').attr('disabled', 'disabled');
</script>