Q: i am locked out of i phone

Read this:

http://support.apple.com/kb/HT1212

Put iPhone in DFU mode > Restore via iTunes.

Will solve the problem.

Did you put a passcode lock on the iPhone or a SIM lock?

If it's a passcode lock and you can't remember the passcode, you'll have to restore the iPhone as outlined here -> iOS: Device disabled after entering wrong passcode

If it's a SIM Lock and you can't remember the pin, you'll get three tries before you need a new SIM. You shouldn't have to restore, but if you do, you may be able to pop the SIM out and then restore the iPhone.

what is DFU mode and how to do it?

Google it.