jQuery Forum

1. $('select[name^="categories"]').change(function(){
      var base_url = 'http://'+window.location.host;
      var script_url = base_url + "buildDropdown";
      var index = $(this).attr('name').split('_');
      console.log(index);
      $.ajax({
         url: script_url,
         data: {
            categoryID: $(this).val()
            },
         type: "POST",
         success: function(data){
            $('select[name="subcategories_' + 
         index[1] + '"').html(data);
         }
      });
   });

2. <td><select name="categories_0">
3. <option value="8">Pay</option>
4. <option value="9">Property</option>
5. <option value="10">Shares</option>
6. <option value="0">Select Category...</option>
7. </select></td><td><select name="subcategories_0">
8. <option value="0">Select Subcategory</option>
9. </select></td>

$('select[name="subcategories_' + index[1] + '"').
      html(data);