Why isn't tint color working in this shader?

Hey all. I’m no scripting pro and this is driving me crazy. This shader is exactly what I need, except for the fact that the tint color isn’t having any effect, and all textures that I plug in for the sprite texture show up white, regardless of the RGB values. Please help!

Shader “AlphaMask” {

Properties {
_MainTex (“Sprite Texture”, 2D) = “white” {}
_Color (“Tint”, Color) = (1,1,1,1)
_AlphaTex (“Alpha (A)”, 2D) = “white” {}
}
SubShader {
Tags { “RenderType” = “Transparent” “Queue” = “Transparent+1”}
ZWrite On
ZTest LEqual

ColorMask RGB

Blend SrcAlpha OneMinusSrcAlpha

Pass {
cull off
SetTexture[_MainTex] { Combine texture }
SetTexture[_AlphaTex] { Combine texture, previous * texture}
}
}
}

Also if it would be possible to make the alpha of the main texture keyable, that would be superb.