I went to one of the AT&T store near my house and told them that I want to buy an iPhone. They asked my name and hand me the contract that says " You must activate the iPhone with AT&T!!! but I just want to buy it and used it with T-mobile. I don't want to signed 2 years contract with them. **My Question is " If i buy an iPhone form Apple online store, Do I need to sign any contract before I can buy it like at the AT&T store ,or there is no contract at all ?