Oracle user is locked out

Sqlplus sys/[email protected]: 1521/CMSX as Sysdba

Sql*plus:release 11.2.0.1.0 Production on Monday July 21 13:33:13 2014

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Connect to:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0-production
With the partitioning, OLAP, Data Mining and Real application testing options

Sql> Alert user Cmsuser account unlock;
sp2-0734: Unknown command at the beginning of "Alert user ..."-ignores the remaining lines.
sql> alter user cmsuser account unlock;

The user has changed.

Sql>