title: How to disable value in select option when it already selected by another select option
body: <p>So, i have a simple form like this:</p>
  
  <pre><code>&lt;div class="form-group"&gt;
  &lt;label class=""&gt;No Inventaris&lt;/label&gt;
  &lt;div id="container"&gt;
      &lt;input type="button" name="noInv" class="form-control" id="add_field" value="Klik untuk membuat text field baru"&gt;&lt;br&gt;
      &lt;script type="text/javascript"&gt;
      var count = 0;
      $(function(){
          $('#add_field').click(function(){
              count += 1;
              $('#container').append(
                  '&lt;strong &gt;No Inv Barang Ke ' + count + '&lt;/strong&gt;&lt;br /&gt;' 
                  + '&lt;select id="field_' + count + '" name="fields[]' + '"  class="form-control no_inv"&gt;&lt;?php $noInv = $this-&gt;modelku-&gt;select_inv() ?&gt; &lt;?php foreach($noInv-&gt;result() as $inv){ ?&gt; &lt;option value="&lt;?php echo $inv-&gt;no_inv ?&gt;"&gt;&lt;?php echo $inv-&gt;no_inv ?&gt;&lt;/option&gt;&lt;?php } ?&gt;&lt;/select&gt;&lt;br&gt;' );
  
          });
      });
      &lt;/script&gt; 
  
  &lt;/div&gt;
  </code></pre>
  
  <p></p>
  
  <p>When i click the button the field will regenerate select option, and the value is from database</p>
  
  <p>select_inv function:</p>
  
  <pre><code>public function select_inv()
  {
      $this-&gt;db-&gt;select("no_inv");
      $this-&gt;db-&gt;from('detail_barang');
      $this-&gt;db-&gt;where("kondisi = 'Ada' ");
      $query = $this-&gt;db-&gt;get();
      return $query;
  }
  </code></pre>
  
  <p>My Question: How can i disable value in select option when it already selected by another select option?</p>