[Freeswitch-users] hangup_after_hook after txfax

I'm trying to get the mod_span vaialbes after fax sent fax_success and fax_result_text with following in dialplan <action application="set" data="api_hangup_hook=system /usr/local/bin/php /usr/local/freeswitch/scripts/phptest.php ${dialed_extension} ${fax_file} ${fax_success} ${fax_result_text}"/> but these vars are empty. is there any example to get these vars after hangup ? Thanks Franck