Correct Unlit Shader to use when Fading a Material

I have a texture applied to a plane, and wish to dynamically set the alpha. The problem is fading the texture using the alpha channel of material.color, after manually assigning the colour white at start.

I have this script which works when using the default transparent diffuse, but not any of the unlt shaders. The shaders for unlit from owlchemy labs didnt work either, even though I can see the alpha bar moving up and down.

theMaterial = gameObject.renderer.material;
theMaterial.color = Color.white;

theMaterial.color = Color( theMaterial.color.r, theMaterial.color.g, theMaterial.color.b, health * 0.01 );

How do I change the alpha of a texture using an unlit shader? Which shader should I use? Does anyone have a link to a shader (shaderlab and UnityGems are my first call when have time to learn CG and shaders). Thanks =]

Owlchemy Labs Unlit Alpha Shader :

//Originally by Bill Vinton (Sync1B)

Shader "Unlit/AlphaSelfIllum" {
    Properties {
        _Color ("Color Tint", Color) = (1,1,1,1)
        _MainTex ("SelfIllum Color (RGB) Alpha (A)", 2D) = "white"
    Category {
       Lighting On
       ZWrite Off
       Cull Back
       Offset -1, -1
       Blend SrcAlpha OneMinusSrcAlpha
       Tags { "Queue" = "transparent" }
       SubShader {
            Material {
               Emission [_Color]
            Pass {
               SetTexture [_MainTex] {
                      Combine Texture * Primary, Texture * Primary

Not sure if this is the best way, but it worked for me.

In the Material add:

Diffuse [_Color]