Foxycart snippet for no tax coupon

gistfile1.txt

(function (FC, $) {
  FC.wholesaleCoupon = {};
  FC.wholesaleCoupon.execute = function() {
    var is_w = false;
    for (item in FC.json.coupons) {
      if (~item.indexOf('FRIEND')) {
        is_w = true;
      }
    }
    if (is_w)  {
      // This works - the field gets updated - 
      $('#shipping_tax_id').val('friend');
      $('#billing_tax_id').val('friend');
      
      
      // None of the above seem to update taxes
      FC.json.taxes_calculated = true; // tried false
      FC.cart.recalculateCartTotals();
      FC.cart.renderTaxes();
    }    
  };
 
  function wholesaleCouponHandler(){
    FC.wholesaleCoupon.execute()
  }
   
   FC.client.on("checkout-shipping-options-update.done",wholesaleCouponHandler);
   FC.client.on("checkout-submit",wholesaleCouponHandler);
   FC.client.on("customer-login.done",wholesaleCouponHandler);
   FC.client.on("cart-coupon-add.done",wholesaleCouponHandler);
   FC.client.on("cart-coupon-remove.done",wholesaleCouponHandler);

  {% if cart_is_fullpage or context == 'checkout' %}FC.client.on("ready.done",wholesaleCouponHandler);{% endif %}
})(FC, jQuery);