Virtuemart: Creating all JFBCComments in parent product

global $CurrentItemID;
$CurrentItemID = $this->product->virtuemart_product_id;

function GetParentID($productId)
{
	$database = JFactory::getDBO();
	
	$query = "SELECT `p`.`product_parent_id`";
	$query .= " FROM `#__virtuemart_products` AS `p`";
	$query .= " WHERE `p`.`virtuemart_product_id` = '{$productId}'";
	
	$database->setQuery($query);
	$row = $database->loadObject();

	if (!$row) {
		return 0;
	}
	else {
		return $row->product_parent_id;
	}
}

function parentProductURL() {
	global $CurrentItemID;
	$ParentID = 0;
	$FirstPart = 'https://'.$_SERVER['SERVER_NAME'].'/index.php?option=com_virtuemart&view=productdetails&virtuemart_product_id=';
	$LastPart = "";

	$loop_ParentID = GetParentID($CurrentItemID);
	do {
		$ParentID = $loop_ParentID;
		$loop_ParentID = GetParentID($ParentID);
	} while ($loop_ParentID != 0);
	
	
	if ($ParentID == 0) {
		$LastPart = $CurrentItemID;
	} else {
		$LastPart = $ParentID;
	}
	return $FirstPart . $LastPart;
}

<?php echo '{JFBCComments href=' . parentProductURL() . '}'; ?>