Oracle Database Discussions

Hi all

I am trying to Export the Scott schema using the following command

c:\>exp sys/password file=scott.dmp log=scott.log owner=scott
Error:
Exp-00056: Orace error 28009 encountered
ORA-28009: connection to sys should be as sysdba or sysoper
Note : I entered the User name and password again
Username:sys
password:Password
Exp-00056: Orace error 28009 encountered
ORA-28009: connection to sys should be as sysdba or sysoper
UserName:system
Password:manager
EXP-00057: ORACLE error 1017 encountered
ORA-01017: invalid username/password;logon denied
EXP-0005: all allowable logon attempts failed
EXP-00000: Export terminated unsuccessfully;
Note: I am using the same Sys/password for login to database.I dont know why i am getting this error. can any one please help me

Thanks in Advance