How to control item attribute in oracle forms

set_item_instance_property or app_item_property.set_property

if :KD = 2 then
:PRESSURE_TEST := 'N';
SET_ITEM_INSTANCE_PROPERTY('CYL_CYLINDER_BASE_DATA.PRESSURE_TEST',CURRENT_RECORD, UPDATE_ALLOWED, PROPERTY_FALSE);
else
:PRESSURE_TEST := 'Y';
SET_ITEM_INSTANCE_PROPERTY('CYL_CYLINDER_BASE_DATA.PRESSURE_TEST',CURRENT_RECORD, UPDATE_ALLOWED, PROPERTY_TRUE);
end if;