hi i bought an iphone off a friend today for a cheap price its the 1st gen running 3.1.3 firmware 8 gb and i was wondering if i could use a brand new unactivated AT&T sim card like off amazon to activate my iphone with because i dont want to use my simcard because AT&T will charge me the data plan which im not trying to pay so please help me out ive been searching through youtube and google all day and the power button is broken on the iphone