Change here the attenuation parameters of the light (or list of lights,
previously selected with Light->Select, when 
Global is pressed).
Parameters for empty entries or 
Local choices remain unchanged.
Axial
Change the 
Constant, 
Linear, 
Quadratic parameters 
that control the axial attenuation. This is defined only for positional
and spot lights. The axial attenuation factor is given by:
Axial Attenuation Factor = 1/(constant + linear*distance + quadratic*distance*distance)
Radial
Change the radial attenuation, defined only for spot
lights. The radial attenuation factor is given by:
Radial Attenuation Factor = [max (0, vertex . direction)]**radial