Unlocking and flashing questions

hi

i akm wondering ho do i find out what my MAIN and FS are??

help would be great thanx

Connect your phone to XS++ and you will find the version of the firmware and CDA.
XS++ 3.1 Guide-Flashing,Customizing,Recovering - Top Sony Forums

or

Enter in the secret menu on the phone: press > * < < * < * - Service info - Software info