Go to phone settings you will be having an option master reset, press this one (note: you will loose all your current settings)
If you have forgot your phone lock code and you want to unlock it or wnt to reset your phone,
then all you have to do is to type this code at your normal dial screen:
(Note:This code will reset your phone to default settings
and all your data that is stored on your phones memory will
be erased,so store your important data on your memory card before you type this code.