Need help setting a keyped lockcode on alcatel 356 | Phone/Device Issues and Features | Consumer forum

Does anyone know how to set a keypad lockcode for when the alcatel 356 when it is not in use?
I know if you push the space bar it will lock it, but to unlock the phone all you have to do is press the spacebar and then when it asks you if you want to unlock the phone, you press the "yes" button.
So if you lose your phone and someone finds it, your phone is at their mercy. Or if your girlfriend picks up your unlocked phone and finds all of your naughty texts to your other girlfriend, then you are in big big trouble.
I figured out how to set a code for when I turn the phone completely off and then power on, but that isnt practical because then you can miss important calls and texts.
Most phones I've seen, you press the spacebar or something simple like that to lock it, and when you want to use it you enter your code and you are rockin.
Input would be much appreciated. Thanks.