DECLARE
   l_user_cnt        NUMBER;
   l_user            NUMBER;
   l_install_date    DATE;
   l_expiry_period   NUMBER := 10;              -- Expiry Day is after 10 days
   l_license         VARCHAR2 (50) := 'ABCD1234EFGH'begin

BEGIN 
      begin
        select user_id,install_date
        into   l_user,l_install_date
        from   user_installations; -- A table which holds data related to all the users who installed the application
       exception when no_data_found then
                -- Create new users entry in user_installation table by inserting the record
       exception when others then
                -- Take actions accordingly
       end;

       -- Check whether the license is going to expire or not
           if sysdate-l_install_date>10 then
                -- Display message about expiry and ask user to provide the license in a text item
                -- once the user enters the license, compare the value with actual license
                        if incoming_license_value=l_license then
                            -- Allow the user to open the form
                        else
                            -- Display message about invalid license
                            -- Take the required action
                        end if;
          else
          -- Display message that the license will expire in l_expiry_period - (sysdate-l_install_date)
          -- Open the form
          end if;
END;