hi there here's the code to reset your phone
inter this code *2767*3855# without simcard. ok!
the code is 1234 or 0000 if non of this work then plz go to the site www.unlock-samsung.eu
you are talking about the security lock code to enter into the phone
then once it is lost nothing can be done except flashing the mobile .
Because if anybody can give the security code created then who ever who
steals your phone can get into it and get your valuable information.
So as safety precaution to avoid that they have designed it such that if
you forget the security lock you have to reset the mobile memory by
flashing the mobile at an authorized service center.So while flashing
the mobile all the data in the mobile memory will be lost and you can
again start using the mobile.
Only way to reset it is to flash your phone. Search internet for flash files and flasher. After flash your phone will be set to default one!