How does one add Illumination to a shader?

I am extremely inexperienced with shader code, but unfortunately I must dive in.
So, I have this shader that has: Diffuse, Normal, Reflection and Specular. I need to add Illumination to it.

Code (CSharp):

1. //Hard Surface Shader Package, Written for the Unity engine by Bruno Rime: http://www.behance.net/brunorime brunorime@gmail.com
2. Shader "HardSurface/Hardsurface Free/Opaque Specular"{
3. Properties {
4.     _Color ("Main Color", Color) = (1,1,1,1)
5.     _SpecColor ("Specular Color", Color) = (1, 1, 1, 1)
6.     _Shininess ("Shininess", Range (0.01, 3)) = 1.5
7.     _Gloss("Gloss", Range (0.00, 1)) = .5
8.     _Reflection("Reflection", Range (0.00, 1)) = 0.5
9.     _Cube ("Reflection Cubemap", Cube) = "Black" { TexGen CubeReflect }
10.     _FrezPow("Fresnel Reflection",Range(0,2)) = .25
11.     _FrezFalloff("Fresnal/EdgeAlpha Falloff",Range(0,10)) = 4
12.     _EdgeAlpha("Edge Alpha",Range(0,1)) = 0
13.     _Metalics("Metalics",Range(0,1)) = .5
14.  
15.     _MainTex ("Diffuse(RGB) Alpha(A)",2D) = "White" {}
16.     _BumpMap ("Normalmap", 2D) = "Bump" {}
17.     _Spec_Gloss_Reflec_Masks ("Spec(R) Gloss(G) Reflec(B)",2D) = "White" {}
18.     _Illum ("Illum (RGB)", 2D) = "black" {}
19.  
20. }
21.  
22.     SubShader {
23.      
24.         Tags {"Queue"="Geometry" "RenderType"="Opaque" "IgnoreProjector"="False" }
25.         UsePass "Hidden/Hardsurface Pro Front Opaque Specular/FORWARD"
26.      
27.     }
28.         Fallback "Diffuse"
29.     }
30.  

I've been searching for a solution all day, and I haven't found anything that could help me.

 

I don't believe your fallback Diffuse has an Illumination channel. Using a fallback of "Self-Illumin/Diffuse" should fix that.

 

I don't see any difference.