you have to do hardreset to clear password if you can't unlock it. try to remove the battery while phone is still on. It should erase password. put battery back and turn on phone.
If that doesn't work then you'll have to get your PUK from your provider. You'll have to check the manual for the sequence to put it in though. I can't remember what it is. I'm assuming that you forgot the code then set it to lock. I've done this before and locked my SIM card (GSM phone).
Did you ever change the code yourself or a previous owner? If not. the default should be 0000 or 00000 (zeros), I can't remember which PIN is for which lock.
This phone has a password in it that it ask for when the phone comes on. I have tried all the "factory" passwords, but to know avail.. I'm just at a loss.. He can send to the local provider to see if they can "unlock" it.. My mind is tired...
When the phone is powerered on and displays "Enter Unlock Code:" press menu. The display should then change to "Enter Security Code:"
Try the default (which should be 000000 aka 6 zeros) followed by pressing the right smart select button (which should be labeled as "OK" on the screen.
If the security code has been changed from the default, there is no easy way for the user to bypass it. Please let me know if the security code bypass works, and I'll walk you through resetting the unlock code.