can any tell me is there a lighting system that switches on when you enter a room etc and switches off after 15 mins when no one is in that room or particular area thanks for any suggestions or information
They do exist, our local newly built hospital has such a system. It has problems. If you sit still as when watching tv or reading for instance, the lights go out and if you are asleep in bed and roll over or throw the covers off, the lights go on.
Just a thought to bear in mind - lights that automatically time out often work on movement sensors. So if you are happily sitting still, they often will switch off leaving you in the dark, which can be irritating.
Movement sensors (PIR) are likely to give the problems that the others have mentioned.
If you need a fixed time of 15mins, then a time-delay switch would do it. These can be of the pneumatic type (big button pushed in, then it slowly creeps out to switch off.)
.... or ..... modern electronic ones are adjustable over quite a long "on" period