DEFAULT_VALUE(NULL, 'GLOBAL.TXTDEPTNO');
  IF :GLOBAL.TXTDEPTNO IS NOT NULL THEN
          -- restrict the query of the EMP-block
           :GLOBAL.AUTOQUERY:='TRUE';
       GO_BLOCK('EMPLOYEES');
         -- automatic query
       EXECUTE_QUERY;
          :GLOBAL.AUTOQUERY:='FALSE';
  END IF;

    IF :GLOBAL.AUTOQUERY='TRUE' THEN
       :EMPLOYEES.TXTDEPTNO:=:GLOBAL.TXTDEPTNO;
    END IF;

DECLARE
      v_empno employees.employee_id%TYPE;
      v_name employees.last_name%TYPE;
  CURSOR emp_cursor IS
         SELECT employee_id,
                last_name
                FROM employees
                WHERE department_id = 
                &p_deptno;
   BEGIN
          OPEN emp_cursor;
          LOOP
          FETCH emp_cursor INTO v_empno, v_name;
   EXIT WHEN emp_cursor%NOTFOUND;

          DBMS_OUTPUT.PUT_LINE
          ('The number of employee is '
          ||
            TO_CHAR (v_empno)
          ||
           ' and his last name is '
          || TO_CHAR(v_name));
   END LOOP;
         CLOSE emp_cursor;
   END;
/

 IF :CONTROL.A IS NOT NULL THEN 
       SET_BLOCK_PROPERTY('EMP',DEFAULT_WHERE,'EMP.JOB LIKE :CONTROL.A');
   END IF;
   
   IF :CONTROL.B IS NOT NULL THEN 
       SET_BLOCK_PROPERTY('EMP',DEFAULT_WHERE,'EMP.SAL LIKE :CONTROL.B');
     ELSE
       SET_BLOCK_PROPERTY('EMP',DEFAULT_WHERE,'EMP.JOB LIKE :CONTROL.A OR EMP.SAL LIKE :CONTROL.B');
   END IF;

GO_BLOCK('EMP');
EXECUTE_QUERY;