Can I buy a phone from AT&T Non Contract and Use it on the Rogers Network in Canada?

AT&T uses sim card when you buy a phone from them it may be locked.If you want to use Rogers networks service on your HTC phone means,you will need to remove AT&T network lock.Through the network unlock code,you will be able to remove network lock on your phone.For getting unlock code you can approach your service provider or else try to buy an unlock code from any one of the online unlocking service provider like OnlineGSMUnlock.com Once unlock it,you will be able to use your rogers network.