To tighten security, the GAO building was declared 'closed' by the General Services Administration, which permits better control of public access to the building. Turnstiles have been installed at main entrances and can be operated only with magnetically encoded identification cards. All other visitors must be identified and checked in by the contract guard force or by the GAO receptionists. Sensitive locations within the building are equipped with their own access control readers to prevent access by unauthorized personnel. Barriers have been installed between the first floor and basement stairwells to thwart property theft. Security briefings and seminars have been held to advise GAO employees of the potential threat of hostile intelligence efforts. The personnel security program is being revised to permit categorization of all GAO positions according to security requirements, which will facilitate determining the type of background investigation needed for each position. GAO is also stepping up action to thwart the use of any electronic surveillance by hostile intelligence. To help ensure employee safety a building-wide HELP-line has been introduced for bringing immediate assistance. The number rings simultaneously in the security office and at the guard desk and is intended for use only in medical emergencies, suspected fires, or other type of emergency help. GAO employees leaving the building later than normal working hours have the benefit of a shuttle to neighboring parking lots every 15 minutes. Additional building parking spaces for employees have also been obtained. This is to guard against muggings. Additional security and safety procedures are currently being planned.