set user restrictions

[zyrie15]

after two days of coding, I finally found out what to do with my previous problem of being able
to prompt a username based on a table. now if anyone is kind enough to please teach me how can I
set restrictions to users based on the following conditions:

for a user to insert and update, he/she must have a username with a granted_role of doc_maint
and expiry date (NOTE: BOTH are columns in the table clm_usr together with the column username) must be NULL.
else, all users who do not meet the conditions are only allowed to view data.

here are the codes i need to edit by the way:

BLOCK5 -> LOGIN -> WHEN-BUTTON-PRESSED

DECLARE
 lv_flag_txt CHAR(1);
 lv_member_txt VARCHAR2(25);
BEGIN
 login_sp (:BLOCK5.user, lv_flag_txt, lv_member_txt);
 IF lv_flag_txt='Y' THEN
   GO_BLOCK('LINE');
   /*GO_ITEM('line.line_pref');*/
   execute_query;
 ELSE
   SET_ITEM_PROPERTY('BLOCK5.login_reject', VISIBLE, PROPERTY_TRUE);
 END IF;
END;

---------------------------------

PROGRAM UNITS -> LOGIN_SP(Procedure Body)

PROCEDURE login_sp
(p_user IN VARCHAR2,
 p_flag OUT CHAR,
 p_mem OUT VARCHAR2)
IS
 lv_expiry_dt clm_usr.expiry_dt%TYPE;
BEGIN
 p_flag :='N';
 SELECT expiry_dt
   INTO lv_expiry_dt
   FROM clm_usr
  WHERE UPPER(username)=UPPER(p_user);
 IF SQL%FOUND THEN
   p_flag := 'Y';
 END IF;
EXCEPTION
   WHEN no_data_found THEN
     p_flag := 'N';
   WHEN too_many_rows THEN
     p_flag := 'Y';
 END;