SQL & PL/SQL

Dear friends,
This is kind of a newbie question on GTT..

I have created a Global Temporary table with ON Commit DELETE Rows.
This is my sample procedure..

CREATE OR REPLACE PROCEDURE procheck (mycur OUT sys_refcursor)
AUTHID CURRENT_USER
AS
   l_tname   VARCHAR2 (30) DEFAULT 'temp_table_' || USERENV ('sessionid');
BEGIN
   EXECUTE IMMEDIATE    'create global temporary table '
                     || l_tname
                     || ' on COMMIT DELETE rows as select * from emp where 1=0 ';

   EXECUTE IMMEDIATE 'insert into ' || l_tname || ' select * from emp';

   OPEN mycur FOR 'select * from ' || l_tname || ' order by ename';

   EXECUTE IMMEDIATE 'drop table ' || l_tname;
END;
/

When I am calling the above procedure from SQL*Plus,
I am getting the following error:

SQL> EXEC procheck (:V);

PL/SQL procedure successfully completed.

SQL> print v;
ERROR:
ORA-01410: invalid ROWID



no rows selected