ok thank you - i got a LOT farther along that time! 
what was particularly confusing is that in order to include FaceBook in an app that already successfully uses Google, i had to add one line to the simple code provided to me from the app āquick-startā PHP example:
āscopeā => āopenid email name nickname pictureā, /* add this line* /
this was very confusing, since i just assumed the very simple PHP example provided to me would work with any social media, not just Google.
suggstion: include this line in the PHP example which is displayed when the app is created.
however, this did cause one more very minor issue which i am asking about here.