How to use TTITLE/BTITLE/LEFT/RIGHT(reporting commands) in PL SQL program

How to use TTITLE/BTITLE/LEFT/RIGHT(reporting commands) in PL SQL program.

I tried using in pl/sql program top title/btitle is working or coming up.
When used with sql every thing is working as expected.

PL/SQL program used
===============
set serveroutput on
set head on
TTITLE CENTER "THE XXX LIMITED" SKIP 3 -
LEFT "TEST" -
RIGHT "ANOTHEAR TEST" SKIP1 -
LEFT "======================"
declare
        empno emp1.emp_no%type;
        name varchar2(20);
        sal1 number;
        begin
                select emp_no,emp_name,sal into empno,name,sal1 from
                emp1 where emp_no='125';

                if (sal1>2000.00) then
                        update emp1 set sal=sal1*0.2 + sal1 where emp_no=125;
                else
                        update emp1 set sal=sal1 where emp_no=125;
                end if;
                dbms_output.put_line('Final Number : '|| name);
        end;
/

SQL PROGRAM USED
=================
SET LINESIZE 61
TTITLE CENTER "THE XXXXXXX D" SKIP 3 -
LEFT "TEST" -
RIGHT "ANOTHEAR TEST" SKIP1 -
LEFT "======================"
select * from dual;