How do i get facebook chat in my contacts on my LG Ally for verizon wireless?

when i first got my ally i found an option that let me turn on facebook chat through my concacts. in my contacts it had the green online indicator for all my friends in my contacts that were online in facebook. somehow i managed to turn off that option and now i cant figure out how to get it back. so if anyone has an LG ally and knows what im talking about help me outttttt.