Oracle forgot database password

http://jingyan.baidu.com/article/eae078278680c11fec548509.html

windows：

echo %ORACLE_SID%   
set ORACLE_SID=orcl
sqlplus / as sysdba
alter user you_username identified by you_password;
alter user you_username account unlock;

linux：

echo $ORACLE_SID
set ORACLE_SID=orcl
sqlplus / as sysdba
alter user you_username identified by you_password;
alter user you_username account unlock;