add_action('shopp_cart_updated','add_taxid_tocartdata');
add_action('shopp_cart_retotal','shopp_taxid_override');

function shopp_taxid_override($Total)
{
	global $Shopp;
	if(!empty($Cart->data->Order->Customer->info["taxid"]))
	{
		$Total->taxrate = 0;
	}
	print_r($Total);
	exit();
	return $Total;

}
function add_taxid_tocartdata($Cart)
{
	if(empty($Cart->data->Order->Customer->info["taxid"]))
	{
		$Cart->data->Order->Customer->info["taxid"] = $_POST["shopp_cart_taxid"];
		$Cart->updated = true;
	}
	return $Cart;

}
?>