Now, electronic lockboxes make showing homes much easier. Instead of carrying a pocket full of keys, all an agent needs is a single pad. Realtors must insert their pad in the box and type in a personal identification number to gain access. The PINs are kept in a central computer, and must be renewed every month buy each realtor. This allows the sellers to easily find out how many people are interested in their home, and who has been in at what time. This system also provides much more security. The new lockboxes let the homeowners, and realtors know who is responsible if something goes wrong, whether the realtor left the door to the house unlocked or something was damaged.