1998 Buick Century Owner's Manual - Page 80

Door Locks Unlocked doors can be dangerous. Passengers especially children -- can easily open the doors and fall out. When a door is locked, the inside handle won't open it. Outsiders can easily enter through an unlocked door when you slow down stop your vehicle. or This may not beso obvious: You increase the chance of being thrown out of the vehicle in a crash if the doors aren't locked. Wear safety belts properly, lock your doors, and you will be far better off whenever you drive your vehicle. -- From the inside, tolock or unlock the door manually, push the lever forward to lock the door. To unlock, push the lever rearward. There are several ways to lockand unlock your vehicle. From the outside, use your door key or remote keyless entry transmitter.