public function delete($oid = null)
	{
		$k = $this->_tbl_key;

		if ($oid)
		{
			$this->$k = $oid;
		}

		$query = $this->_db->getQuery(true)
			->delete($this->_db->quoteName($this->_tbl))
			->where($this->_db->quoteName($this->_tbl_key) . ' = ' . $this->_db->quote($this->$k));
		$this->_db->setQuery($query);

		$this->_db->execute();

		return true;
	}