I have created a custom taxonomy and want to have a image option for each category.

```
  function create_product_taxonomies()
  {
     // Add new taxonomy, make it hierarchical (like categories)
     $labels = array(
        'name' => _x('product_categories', 'taxonomy general name'),
        'singular_name' => _x('Product', 'taxonomy singular name'),
        'search_items' => __('Search Product Category'),
        'all_items' => __('All Product Categorie(s)'),
        'parent_item' => __('Parent Product Category'),
        'parent_item_colon' => __('Parent Product Category:'),
        'edit_item' => __('Edit Product Category'),
        'update_item' => __('Update Product Category'),
        'add_new_item' => __('Add New'),
        'new_item_name' => __('New Product Name'),
        'menu_name' => __('Product Categories'),

        );

   $args = array(
       'hierarchical' => true,
       'labels' => $labels,
       'show_ui' => true,
       'show_admin_column' => true,
       'query_var' => true,
       'rewrite' => array('slug' => 'product_categories', 'with_front' =>      true));

  register_taxonomy('product_categories', array('products'), $args);
  flush_rewrite_rules();
  }
  //hooks
  add_action('init', 'create_product_taxonomies', 0);

```

How can I provide user the option to upload a image for each category?