Security measures include both physical and psychological deterrents. Businesses should have solid doors, with solid pin hinges and double deadbolt locks requiring a key on both sides. Display windows should be uncluttered. Lighting should be ample both inside and outside, with no shadows inside. Movable grillwork should be installed over windows. To harden the target, all valuables should be placed near the cash register, which itself should be located far from the door. Lighting around the cash register should be particularly bright, and the cash register drawer should be left open to show that there is no money inside. All property should have the owner's social security number engraved on it and a list of these valuables should be mailed to the insurance company. Businesses should follow a checklist at opening and closing time to make sure that all security measures have been taken. Everyone who has a key to the door should be listed; when an employee who has had a key leaves the company, the lock tumbler should be changed. Business people should also lobby their local government to install sodium vapor lights, since these deter burglaries, assaults, and even traffic accidents. If businesses follow these measures, their chance of being burglarized will be lessened.