public function clear()
	{
		$cvars = get_class_vars(__CLASS__);

		$this->_updatedkeys = array();

		foreach ($cvars as $key => $value)
		{
			if ($key{0} != '_')
			{
				unset($this->$key);

				$this->$key = null;
			}
		}

		$this->_updatedkeys = array();
	}