function add_product_item(id) {
    $('cart-count').innerHTML = 'Please Wait...';
    new Ajax.Request('/cart/add_item/' + id, {  
        onSuccess: function (response, json) {
            $('cart-count').update('View Your Cart (' + json.total_count + ')');
            $('store-checkout-form').removeClassName('hidden');

            show_message_box(json.product.title + ' is added to your cart. <a href="/cart">Checkout now?</a>');
        }
    });
}

function remove_product(id) {
    if (confirm('Are you sure want to delete these products from your cart?')) {

        show_wait_image('total-price');

        new Ajax.Request('/cart/remove_items/' + id, {  
            onSuccess: function (response, json) {    
                if (json.items_count > 0) {
                    $('product-row-' + id).remove();
                } else {
                    $('product-row-' + id).update('<p>Your cart is empty</p>');
                    $$('input[name=update]', 'input[name=check_out]', '#cart-totals').invoke('remove');
                }                        
                $('total-price').update('$' + format_currency(json.total));                
            }
        });   
    }
}

function update_product_count(id) {
    var count = parseInt($F('product-count-' + id));
    
    if (isNaN(count) || count < 0) {
        set_background_error_color('product-count-' + id);
        return false;
    } else {    
        set_background_default_color('product-count-' + id);
    }

    show_wait_image('product-total-price-' + id);
    show_wait_image('total-price');

    $$('input[name=check_out]').each(function(el) {
        el.setAttribute('disabled', true);
    }); 

    new Ajax.Request('/cart/update_count/' + id + '/' + count, {  
        onSuccess: function (response, json) {    
            $$('input[name=check_out]').each(function(el) {
                el.removeAttribute('disabled');
            }); 
            $('product-total-price-' + id).update('$' + format_currency(count * json.price));
            $('total-price').update('$' + format_currency(json.total));
        }
    });   
}