this option is enable in 4.0 ics.
but it disabled in higher version of android(4.1+ high).
i tried alot....
in xda and in out side also
my phone is rooted .
it have cwm rom v18.104.22.168 edited by xda developers
and i got this methord from xda . perfectly rooted. and supersu installed.
how can sync my fb with contact ?
is there any method to do so in 4.2.1 ?
please help me.........