Question: Used iphone4s with passcode, I bought it from craigslist but it still has passcode activated

I bought a iPhone 4S from the seller, i quickly deleted my old iphone 3gs information before hand so i could transfer it to my new phone. Thing is, the seller unlocked his 4-digit passcode and showed me the phone still worked, but forget to delete the passcode afterwards. therefore when i "hard reset" the phone and connect it to iTunes 11, I am given the option to reset to the phone to defualt setting, inadvertently the phone can not reset due to password restrictions on " XXXXX's iPhone" (Disclossed the Name). Is there a way to completely restart the iphonewithout having the orginial iPhones 4 digit password/ or the email that it pretains to?.