PAGE RADIO BUTTONS and APPLICATION ITEM VALUE

Question

I have several pages that use same radio button group that permits filtering the report query (of course on each page, it is a page level radio button item).
I created an application item value to hold the last used value of a radio button item.
On login, I would like the application item value set to a default value.
For a given page using the recurring radio button group item,
I would like the radio button item value set to the application item value on entry into a page.
I would like the report to use the application item value on entry to a page.
I would like the application item value be updated anytime the page level radio button item value is changed, so that when you move to another page,
the next radio button group and report can use the last selected radio group button value.
I am trying to use a variety of solutions in COMPUTATION and CONDITIONAL COMPUTATION... to include use of set_session_state procedure, and I am not getting desired result, partial success, but not complete.
Can you have a computation item that is only for initialization of the report and radio button group on page entry?
And a separate computation item that senses user selection of another radio button, updating the report, and updating the application level item?
Help requested. Thank you.
Would be nice to have application level objects, like radio button groups.

Answer 1

Created Page 0
Created an HTML region in COLUMN 2 and SEQUENCE 10.
Selected under region CONDITION:
Current Page is contained within Expression 1 as comma delimited list of pages
in the EXPRESSION 1 provided the requested comma delimited list of pages that I wished the HTML region to appear.
Created the radio button group item P0_RADIO and assigned to Page0 HTML region.
Selected under item CONDITION:
Current Page is contained within Expression 1 as comma delimited list of pages
in the EXPRESSION 1 provided the requested comma delimited list of pages that I wished theradio button group to appear.
In SHARED COMPONENTS I created an APPLICATION COMPUTATION
In the computation I created a PL/SQL function to initialize the radio group
BEGIN
IF :P0_RADIO IS NULL THEN
RETURN 'A_ALL';
ELSE
RETURN :P0_RADIO;
END IF;
END;
'A_ALL' being the default value for :P0_RADIO
Radio group appears on the desired pages, is initialized to the desired default value, and works properly on each page.