BEGIN
            cbcnt := 1;

            FOR x IN (SELECT DISTINCT customer_id
                                 FROM HSS_DEL_TBL_BILL)
            LOOP
               INSERT INTO IVR_TEMP
                  (SELECT     cbcnt, customer_id, LEVEL
                         FROM customer_all
                        WHERE paymntresp IS NULL AND cstype = 'a'
                   CONNECT BY PRIOR customer_id = customer_id_high
                   START WITH customer_id = x.customer_id
                   UNION
                   SELECT cbcnt, x.customer_id, 1
                     FROM DUAL);

               cbcnt := cbcnt + 1;
               COMMIT;
            END LOOP;
         END;

MYDBA@orcl > create table test(a varchar2(10));

Table created.

MYDBA@orcl > insert into test select dummy from dual;

1 row created.

MYDBA@orcl > select * from test;

A
----------
X

1 row selected.