Untitled

<body>
           <br /><br />
           <div class="container">
                <h3>
                     <select name="brand" id="brand">
                          <option value="">Show All Product</option>
                          <?php echo fill_brand($connect); ?>
                     </select>
                     <select name="goal" id="goal">
                          <option value="">Show All Product</option>
                          <option value="test">test</option>
                     </select>
                     <br /><br />
                     <div class="row" id="show_product">
                          <?php echo fill_product($connect);?>
                     </div>
                </h3>
           </div>
      </body>
 </html>
 <script>
 $(document).ready(function(){
      $('#brand').change(function(){
           var brand_id = $(this).val();
           $.ajax({
                url:"load_data.php",
                method:"POST",
                data:{brand_id:brand_id},
                success:function(data){
                     $('#show_product').html(data);
                }
              });
            });
      $('#test').change(function(){
          var goal_id = $(this).val();
          $.ajax({
              url:"load_data.php",
              method:"POST",
              data:{test_id:test_id},
              success:function(data){
                    $('#show_product').html(data);
              }
          });
      });
 });
 </script>