public function updateTag($photo, $to, $x = null, $y = null)
	{
		// Set POST request parameters.
		$data['to'] = $to;

		if ($x)
		{
			$data['x'] = $x;
		}

		if ($y)
		{
			$data['y'] = $y;
		}

		return $this->createConnection($photo, 'tags', $data);
	}