iPhone 4 and 3g for swap for white iPhone 4s or white 4 .

I have a 16 gig black iPhone 4 in perfect condition one or 2 wee scratches nothing bad apart from that very good phone Also have a iPhone 3G perfect working order but not the best condition and also has a cracked outer screen but this dose not effect the phone what so ever I would like to swap both for a white iPhone 4s or a 16 gig white iPhone 4