How can I hide the block if the cart is empty?

I fixed it. Unfortunately I have never made a patch and I am swamped in work and don't have the time to create one now.

This is what I did (new lines marked with "+")

/**
* Implements hook_block_view().
*/
function dc_ajax_add_cart_block_view($delta = '') {
+$commerce_cart = dc_ajax_add_cart_get_commerce_cart_details();
+$line_items = $commerce_cart['wrapper']->commerce_line_items;
+$quantity = commerce_line_items_quantity($line_items, commerce_product_line_item_types());
$block = array();
switch ($delta) {
case 'ajax_shopping_cart':
+ if($commerce_cart['order'] && $quantity != 0){
$block['subject'] = t('Shopping cart');
$block['content'] = dc_ajax_add_cart_get_shopping_cart();
+ }
break;

case 'ajax_shopping_cart_teaser':
$block['content'] = dc_ajax_add_cart_get_shopping_cart_teaser();
break;
}

return $block;
}

Now I would love to be able to update the block with AJAX so it hides when you delete an item from the cart.