debug log for ga result on apm

Hi 

how to show  ga result on apm log local

here is my irule

                if { $ga_code_attempt eq $ga_code } {

                    # code verification successful

                    set ga_result 0

                } else {

                    # code verification failed

                    set ga_result 1

                }

            } elseif { [string length $ga_key] > 0 } {

                # invalid key length, greater than 0, but not length not equal to 16 chars

                set ga_result 3

            } else {

                # could not retrieve user's key

                set ga_result 2

            }

        } else {

            # user locked out due to too many failed attempts

            set ga_result 4

        }

        ACCESS::session data set session.custom.ga_result $ga_result

because on apm log only show 

Executed agent '/Common/authn_and_authz_act_irule_event_ag_3', return value 0 ('Execution Done')

Following rule 'Failed' from item 'GA Verify' to terminalout 'AuthN Failed'

is that correc to add commend like this ?

ACCESS::session data set session.custom.ga_result $ga_result

log local0. "result $ga_result"