check user_id
check user_id
check user_id
check if user is connected using fb-js-sdk
check if user is connected using fb-js-sdk
check if user is connected using fb-js-sdk
login to app
login to app
login to app
login to app
login to app
login to app
login to app
login to app
login to app
login to app
login to app
login to app
login to app
login to app