public function sessdb_read($sid) {
		$retval = '';
		try {
			$sql = "SELECT * FROM ". self::tableName ." WHERE session_id=:sid";
			$numRows = $this->db->run_query($sql, array('sid'=>$sid));
			
			if($numRows == 1) {
				$data = $this->db->get_single_record();
				$retval = $data['session_data'];
			}
		}
		catch(exception $e) {
			//no throwing exceptions...

			$this->exception_handler(__METHOD__ .": failed to read::: ". $e->getMessage());
		}
		return($retval);
	}