function xmldb_attforblock_upgrade($oldversion = 0)
{
    global $CFG, $THEME, $DB;
    $result = true;
    /// And upgrade begins here. For each one, you'll need one
    /// block of code similar to the next one. Please, delete
    /// this comment lines once this file start handling proper
    /// upgrade code.
    if ($result && $oldversion < 2008021904) {
        //New version in version.php
        global $USER;
        if ($sessions = $DB->get_records('attendance_sessions', array('takenby' => 0))) {
            foreach ($sessions as $sess) {
                if ($DB->count_records('attendance_log', array('attsid' => $sess->id)) > 0) {
                    $sess->takenby = $USER->id;
                    $sess->timetaken = $sess->timemodified ? $sess->timemodified : time();
                    $sess->description = addslashes($sess->description);
                    $result = $DB->update_record('attendance_sessions', $sess) and $result;
                }
            }
        }
    }
    if ($oldversion < 2008102401 and $result) {
        $table = new XMLDBTable('attforblock');
        $field = new XMLDBField('grade');
        $field->setAttributes(XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, null, null, '100', 'name');
        $result = $result && $table->add_field($table, $field);
        $table = new XMLDBTable('attendance_sessions');
        $field = new XMLDBField('courseid');
        $field->setAttributes(XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null, null, '0', 'id');
        $result = $result && $table->change_field_unsigned($table, $field);
        //        $field = new XMLDBField('creator');
        //        $field->setAttributes(XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null, null, '0', 'courseid');
        //        $result = $result && change_field_unsigned($table, $field);
        $field = new XMLDBField('sessdate');
        $field->setAttributes(XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null, null, '0', 'creator');
        $result = $result && change_field_unsigned($table, $field);
        $field = new XMLDBField('duration');
        $field->setAttributes(XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null, null, '0', 'sessdate');
        $result = $result && add_field($table, $field);
        $field = new XMLDBField('timetaken');
        $field->setAttributes(XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null, null, '0', 'takenby');
        $result = $result && change_field_unsigned($table, $field);
        $result = $result && rename_field($table, $field, 'lasttaken');
        $field = new XMLDBField('takenby');
        $field->setAttributes(XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null, null, '0', 'lasttaken');
        $result = $result && change_field_unsigned($table, $field);
        $result = $result && rename_field($table, $field, 'lasttakenby');
        $field = new XMLDBField('timemodified');
        $field->setAttributes(XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, null, null, null, null, null, 'lasttaken');
        $result = $result && change_field_unsigned($table, $field);
        $table = new XMLDBTable('attendance_log');
        $field = new XMLDBField('attsid');
        $field->setAttributes(XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null, null, '0', 'id');
        $result = $result && change_field_unsigned($table, $field);
        $field = new XMLDBField('studentid');
        $field->setAttributes(XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null, null, '0', 'attsid');
        $result = $result && change_field_unsigned($table, $field);
        $field = new XMLDBField('statusid');
        $field->setAttributes(XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null, null, '0', 'status');
        $result = $result && add_field($table, $field);
        $field = new XMLDBField('statusset');
        $field->setAttributes(XMLDB_TYPE_CHAR, '100', null, null, null, null, null, null, 'statusid');
        $result = $result && add_field($table, $field);
        $field = new XMLDBField('timetaken');
        $field->setAttributes(XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null, null, '0', 'statusid');
        $result = $result && add_field($table, $field);
        $field = new XMLDBField('takenby');
        $field->setAttributes(XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null, null, '0', 'timetaken');
        $result = $result && add_field($table, $field);
        //Indexes
        $index = new XMLDBIndex('statusid');
        $index->setAttributes(XMLDB_INDEX_NOTUNIQUE, array('statusid'));
        $result = $result && add_index($table, $index);
        $index = new XMLDBIndex('attsid');
        $index->setAttributes(XMLDB_INDEX_NOTUNIQUE, array('attsid'));
        $result = $result && drop_index($table, $index);
        $field = new XMLDBField('attsid');
        //Rename field
        $field->setAttributes(XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null, null, '0', 'id');
        $result = $result && rename_field($table, $field, 'sessionid');
        $index = new XMLDBIndex('sessionid');
        $index->setAttributes(XMLDB_INDEX_NOTUNIQUE, array('sessionid'));
        $result = $result && add_index($table, $index);
        $table = new XMLDBTable('attendance_settings');
        $field = new XMLDBField('courseid');
        $field->setAttributes(XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null, null, '0', 'id');
        $result = $result && change_field_unsigned($table, $field);
        $field = new XMLDBField('visible');
        $field->setAttributes(XMLDB_TYPE_INTEGER, '1', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null, null, '1', 'grade');
        $result = $result && add_field($table, $field);
        $field = new XMLDBField('deleted');
        $field->setAttributes(XMLDB_TYPE_INTEGER, '1', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null, null, '0', 'visible');
        $result = $result && add_field($table, $field);
        //Indexes
        $index = new XMLDBIndex('visible');
        $index->setAttributes(XMLDB_INDEX_NOTUNIQUE, array('visible'));
        $result = $result && add_index($table, $index);
        $index = new XMLDBIndex('deleted');
        $index->setAttributes(XMLDB_INDEX_NOTUNIQUE, array('deleted'));
        $result = $result && add_index($table, $index);
        $result = $result && rename_table($table, 'attendance_statuses');
    }
    if ($oldversion < 2008102406 and $result) {
        if ($courses = $DB->get_records_sql("SELECT courseid FROM {attendance_sessions} GROUP BY courseid")) {
            foreach ($courses as $c) {
                //Adding own status for course (now it must have own)
                if (!$DB->count_records('attendance_statuses', array('courseid' => $c->courseid))) {
                    $statuses = $DB->get_records('attendance_statuses', array('courseid' => 0));
                    foreach ($statuses as $stat) {
                        $rec = $stat;
                        $rec->courseid = $c->courseid;
                        $DB->insert_record('attendance_statuses', $rec);
                    }
                }
                $statuses = $DB->get_records('attendance_statuses', array('courseid' => $c->courseid));
                $statlist = implode(',', array_keys($statuses));
                $sess = $DB->get_records_select_menu('attendance_sessions', "courseid = ? AND lasttakenby > 0", array($c->courseid));
                $sesslist = implode(',', array_keys($sess));
                foreach ($statuses as $stat) {
                    execute_sql("UPDATE {$CFG->prefix}attendance_log\n                                        SET statusid = {$stat->id}, statusset = '{$statlist}'\n                                  WHERE sessionid IN ({$sesslist}) AND status = '{$stat->status}'");
                }
                $sessions = get_records_list('attendance_sessions', 'id', $sesslist);
                foreach ($sessions as $sess) {
                    execute_sql("UPDATE {$CFG->prefix}attendance_log\n                                    SET timetaken = {$sess->lasttaken},\n                                            takenby = {$sess->lasttakenby}\n                              WHERE sessionid = {$sess->id}");
                }
            }
        }
    }
    if ($oldversion < 2008102409 and $result) {
        $table = new XMLDBTable('attendance_statuses');
        $field = new XMLDBField('status');
        $result = $result && drop_field($table, $field);
        $index = new XMLDBIndex('status');
        $index->setAttributes(XMLDB_INDEX_NOTUNIQUE, array('status'));
        $result = $result && drop_index($table, $index);
        $table = new XMLDBTable('attendance_log');
        $field = new XMLDBField('status');
        $result = $result && drop_field($table, $field);
        $index = new XMLDBIndex('status');
        $index->setAttributes(XMLDB_INDEX_NOTUNIQUE, array('status'));
        $result = $result && drop_index($table, $index);
        $table = new XMLDBTable('attendance_sessions');
        $field = new XMLDBField('creator');
        $result = $result && drop_field($table, $field);
    }
    return $result;
}