Write a PL/SQL block to find out the start date for current job of a specific employee

DECLARE
    emp_st_date DATE;
    wr_emp_id   employees.employee_id%TYPE := &enter_employee_id;
BEGIN
    SELECT Max(end_date) + 1
    INTO   emp_st_date
    FROM   job_history
    WHERE  employee_id = wr_emp_id;

    IF emp_st_date IS NULL THEN
      SELECT hire_date
      INTO   emp_st_date
      FROM   employees
      WHERE  employee_id = wr_emp_id;
    END IF;

dbms_output.Put_line('----------------------------------------------------------------------');

dbms_output.Put_line('The starting date of current job for the employee  '
                     ||wr_emp_id
                     ||' is: '
                     ||emp_st_date);
END;
/