jquery/javascript select option randomly

Question

I want to select an option from select randomly.

<select class=".sel" id="sel">
    <option>a</option>
    <option>b</option>
    <option>c</option>
    <option>d</option>
</select>

actually i am using jQuery autocomplete.

Well,the question is how can i select option randomly from a select box ?

and what i tried is

function change_something(opt)
    {
    var randomOption=Math.floor(Math.random()*$(opt+' option').size());
    $(opt+ option["value='"+randomOption+"'"]).attr('selected', 'selected');
  }

Actually i am not a jQuery expert,so i am getting failed to change something .

Answer 1

Something like this should work:

var $options = $('#sel').find('option'),
    random = ~~(Math.random() * $options.length);

$options.eq(random).prop('selected', true);

http://jsfiddle.net/elclanrs/8DPMN/