I got the following error when i tried to create a tablespace as follows,

SQL> create tablespace temp1
2 datafile 'c:\oracle\oradata\newdb\new.dbf' size 250k temporary;
create tablespace temp1
*
ERROR at line 1:
ORA-12913: Cannot create dictionary managed tablespace

Can anyone explain me,

1) What is the reason for this error?
2) What i've to do to avoid this error?

Thanks,
Malru