DBMS_OUTPUT issues

Okay, I am trying to get oracle to simply output a line of text onto the screen. For whatever reason, this does not work.
Here is the code I am trying:

set serveroutput on size 40000

DECLARE

output varchar2(20) := 'test output.';
DBMS_OUTPUT.ENABLE(2000);

BEGIN

DBMS_OUTPUT.PUTLINE('print something');
DBMS_OUTPUT.PUTLINE(output);

END;
/

The output.enable line causes the following error:

DBMS_OUTPUT.ENABLE(2000);
*
ERROR at line 4:
ORA-06550: line 4, column 12:
PLS-00103: Encountered the symbol "."

Any help would be great because this problem is really annoying. I am using SQL Plus 8.05.

Thanks

Nevermind, I got it.