我想同时对几条记录更新时间，就像群删的功能

我按照群删的语句
conn.execute "delete from "&db&" where idSerial in ("&id&") "
同样改成群更新的语句
conn.execute "update "&db&" set pRegTime="&now()&" where idSerial in ("&id&") "
出错了，请问应该怎么写？