How to accept a user subscription request?

Hello,

I am developping a Jabber Client and I would like to know what to do when I get a Presence packet of Type suscibe ???

I had the user to my Roster and send back a Presence packet with Type to suscribed but it does not act as an acceptance of this request. How to do ???

Another question is, when I remove a user entries how to avoid him/her to see me ??? use PrivacyList or what is unsuscribe and unsuscribed Presence packets…???

Thank you