Point ligths, attenuation and range

Hi,

I'm trying to use unity_LightAtten[0].z to calculate attenuation ( it's ForwardAdd pass )

Code (csharp):

1.  
2. float atten = 1.0 / ( 1.0 + lengthSq * unity_LightAtten[0].z );
3.  

It looks like unity_LightAtten[0].z is always 0 for point lights. Can't get it working. I can't read the light range either. Changing light range in the editor doesn't affect the way the light works with my model. Are the attenuation and range exposed to the shader? I know there are variables declared in cginc files but values they take don't seem to be correct. I use ForwardBase and ForwardAdd passes to render my model.

Thanks,
Jsr