The Universal World Owner's Manual

$kBuildingIDForProxEvents = 5
$kProxDistanceMeters = 20
$kBuildingHiddenTime = 60

// When player logs in activate a building proximity event for them
//  This means that whenever this player gets within range of the building,
//   the "BuildingProxEnter" event will be triggered
Event( "PlayerLogin", "" )
{
    sysActivateBuildingProximityEvent( $kBuildingIDForProxEvents, $kProxDistanceMeters )
}


// This event will be triggered when the player gets within 20m of Building Number 5
Event( "BuildingIDProxEnter", "$kBuildingIDForProxEvents" )
{
   *grantitem %PLAYER%,1,Special Item
   *setvehicle %PLAYER% 3
   *buildingspecialevent $kBuildingIDForProxEvents 8 $kBuildingHiddenTime 
}