Historical version. PostgreSQL 8.1 has reached end of support. See the current manual.
ALTER USER
Synopsis
ALTER USER name [ [ WITH ] option [ ... ] ]
where option can be:
SUPERUSER | NOSUPERUSER
| CREATEDB | NOCREATEDB
| CREATEROLE | NOCREATEROLE
| CREATEUSER | NOCREATEUSER
| INHERIT | NOINHERIT
| LOGIN | NOLOGIN
| CONNECTION LIMIT connlimit
| [ ENCRYPTED | UNENCRYPTED ] PASSWORD 'password'
| VALID UNTIL 'timestamp'
ALTER USER name RENAME TO newname
ALTER USER name SET parameter { TO | = } { value | DEFAULT }
ALTER USER name RESET parameterReport a documentation issue
Read the upstream documentation. For corrections, first check the current manual.