Enable/Disable a dropdownbox in jquery

I am using JQuery > 1.8 and this works for me...

$('#dropDownId').attr('disabled', true);

Here is one way that I hope is easy to understand:

http://jsfiddle.net/tft4t/

$(document).ready(function() {
 $("#chkdwn2").click(function() {
   if ($(this).is(":checked")) {
      $("#dropdown").prop("disabled", true);
   } else {
      $("#dropdown").prop("disabled", false);  
   }
 });
});