$insert = "INSERT INTO table_name (`field_name`) VALUES ('value')";
    $db_ins=$obj->insert($insert);
    $inserted_id =  mysql_insert_id();

    //update

    $update = "UPDATE `table_name` SET `field_name` = 'value' WHERE `id` = '".$_GET['id']."'";

        $db_updatepage=$obj->edit($update);