attenuation

this is probably very basic stuff but i still got a problem with it:

i’m using a white directional source and a bright green positional light source in my scene. everything works just nicely except for the positional attenuation factor: no matter what values i set for the the constant, linear and quadratic parameters, the light’s strength remains unchanged no matter how far i move away from the source.
what would be typical values for attenuation? what could be the reason it does not work?
english is not my native language anyway, so what does “attenuation” exactly mean? how much the source’s shine strength is decreased in the distance?

thx for any help
eik

check the red book for more detailed info
but set the CONSTANT_ATTENUATION to 0.0 + experiment further