Help for change Order on a form by a trigger!!!!

Question

I'm trying to change order (asc, desc, none) by shooting a trigger!!!
Please Help!!?

Answer 1

here is some code i wrote. hope that hepls.
declare
v_asc varchar2(10) := 'ASC';
v_field_name varchar2(50);
v_prev_orderby varchar2(200);
v_orderby varchar2(200) := ', GIRD_AIR_DT, GIRD_START_TM,GIRD_NETWORK,GIRD_CAT||GIRD_CODE ';
begin     
init_orderby_bar;
v_field_name := upper(replace(:system.trigger_item,:system.trigger_block||'.',''));
if v_field_name = 'GIRD_CATCODE' then
     v_field_name := 'GIRD_CAT||GIRD_CODE';
end if;
v_prev_orderby := upper(get_block_property('GTT_INTRSCH_RANK_DATA',order_by));
if v_prev_orderby like '%'||v_field_name||' ASC%' then
     v_asc := 'DESC';
set_item_property(:system.trigger_item,font_style,font_italic);
else
     v_asc := 'ASC';      
set_item_property(:system.trigger_item,font_style,font_plain);
end if;
v_orderby := v_field_name||' '||v_asc||replace(v_orderby,', '||v_field_name,'');
     set_block_property('GTT_INTRSCH_RANK_DATA',order_by,v_orderby);
set_item_property(:system.trigger_item,font_weight,font_bold);
--     key_exeqry;
execute_trigger('when-tab-page-changed');
end;