jQuery finding dropdown with max selected “rel” attribute

Question

I have a bunch (the exact number may vary) of dropdowns with this code:

<div id="wrapf">
  <div class="dropf">
    <select name="number" id="number" class="options">
      <option value="" rel="">Choose option!</option>
      <option value="1" rel="20">Option 1</option>
      <option value="2" rel="30">Option 2</option>
      <option value="3" rel="40">Option 3</option>
    </select>
  </div>
</div>

I'm trying to set up a function where if I have 2 (or more) of these dropdowns showing, with different selected values, I can highlight the dropdown that has the selected option with the highest rel attribute... I will add the class .highlight to the #wrapf that contains the dropdown with the largest rel.... I have this so far:

Highlight CSS

.highlight {
   box-shadow: 0px 0px 15px rgba(255, 40, 50, 0.4);
   -webkit-box-shadow: 0px 0px 15px rgba(255, 40, 50, 0.4);
   background: rgba(255, 40, 50, 0.4);
}

This is the jQuery:

$("#getMax").click(function () {
    var values = $.map($(".options"), function(el, index) {
        return parseInt($(el).find('option:selected').attr('rel')); 
});        

var max = Math.max.apply(null, values);
var opt = "[rel=" + max + "]";

//doesn't work :(
$('#wrapf').find('option:selected').attr(opt).addClass('highlight');


});​

I think I'm close, just need the final function to .addClass('highlight')!

Answer 1

jsFiddle DEMO

    $("#getMax").click(function (e) {
    var values = $.map($(".options"), function(el, index) {
        return $(el).find('option:selected').attr('rel'); 
        // parseInt() was originally creating a problem as [] turned into NaN
    });     

    var max = Math.max.apply(null, values);

    //works :)
    $('.wrapf').removeClass('highlight'); // remove all other references of highlight
    $('.wrapf').find('select option:selected[rel="' + max + '"]').closest('.wrapf').addClass('highlight');

    e.preventDefault(); // stops anchor from happening

});