Can't Open Sql Pl

[scorpion_ana]

hi all,

i setup oracle 9i
what i should adjust to make it work before i open sql pl
coz ican't connect to the db
i try to open sql pl i input hte account user =scott and pass=tiger it return the error
يوجد خطأ فى موفق الحدمة
ORA-12560
then i open
sql pl work sheet
and aplly the same input put with connecting as dba or sysoper
the output is equel invalid user name and pass