iphone 3g on o2 network +

iphone 3g (not gs) on o2 network but has also been used on orange so i think its unlocked to all networks (ur welcome to try first). only selling as just bought a 4s screen is in good condition, back is scuffed quite abit, also sim tray has broken (i have just ordered a new one which cost one pound of amazon) 65.00 ovno call or text me.