BEGIN 
    FOR date_cur IN (SELECT pay_emp_id, 
                            from_date, 
                            to_date 
                     FROM   pay_emp_itax 
                     WHERE  pay_emp_id = :PAY_EMP_ID) LOOP 
        IF ( :TEXT_FROM_DATE >= date_cur.from_date 
             AND :TEXT_FROM_DATE <= date_cur.to_date ) THEN ---- 
          Message('Overlaping of Dates is not allowed1'); 

          --EXIT; 
          RAISE form_trigger_failure; 
        END IF; 

        IF ( :TEXT_TO_DATE <= date_cur.to_date 
             AND :TEXT_TO_DATE >= date_cur.from_date ) THEN 
          Message('date is not allowd'); 

          --EXIT; 
          RAISE form_trigger_failure; 
        END IF; 
    END LOOP; 
END; 

from date          to date
03-03-2013         10-03-2013

if :text_from_date < date_cur.from_date then
   if :text_to_date < date_cur.to_date then
      ...
   else
      ....
   end if;
else
  if ...