Oracle procedure help

Question

I have table which has 4 cloums, I would like to write procedure
Type varchar2(10)
start Date date
end date date
new_news varchar2(100)
FOR START DATE
Type =A OR B . whatever start-date user type, save as the sunday before (if it is not already a suday)
but if type = C or D, use what ever date user types in
FOR END DAEE
Type =A OR B . whatever start-date user type, save as the sunday before (if it is not already a suday)
but if type = C or D, use what ever date user types in
new_news
if type = A OR B no new_news entry should be allowed
if type=C or D new_news hader can be type in
I need help on writting procedure.

Answer 1

SQL> SELECT sysdate today, NEXT_DAY(sysdate - 7,'Sun') last_sunday,
  2         NEXT_DAY(TO_DATE('03-Jul-2005','dd-Mon-yyyy') - 7,'Sun') keep_sun
  3  FROM dual;
TODAY                 LAST_SUNDAY           KEEP_SUN
Monday    04-Jul-2005 Sunday    03-Jul-2005 Sunday    03-Jul-2005TTFN
John