submit button will do 2 things

this project is on 2.1.2 version
the existing apps will post/submit form and save the input to database...

now i want to make the button will do post the same data to another webservice at another host... what should i do?

how to know what's the detail data posted ... i've found the code related to the page on folder [CI_ROOTDIR]/application/controller/production.php... CMIIW

Note: i have set the print($data) but nothing printed on the page... any pointer will be appreciated