shader Transparency

Hello all
I found a wonderful shader that mixes three colors
but I need alpha transparency to work for the .png textures
I have searched and tried to code no avail

Any Ideas

	Properties
	{
		_MainTex("Main Tex", 2D) = "tranparent" {}
		_Color("Color", Color) = (1.0, 1.0, 1.0, .0)
		_Color1("Color 1", Color) = (1.0, 0.5, 0.5, .0)
		_Color2("Color 2", Color) = (0.5, 0.5, 1.0, .0)
		_Rim("Rim", Float) = 1.0
		_Shift("Shift", Float) = 1.0
	}

	SubShader
	{
		Tags
		{
			"Queue" = "Geometry"
			"PreviewType" = "Sphere"
			"DisableBatching" = "True"
		}

		Pass
		{
			CGPROGRAM
			#pragma vertex Vert
			#pragma fragment Frag

			sampler2D _MainTex;
			float4    _Color;
			float4    _Color1;
			float4    _Color2;
			float     _Rim;
			float     _Shift;

			struct a2v
			{
				float4 vertex    : POSITION;
				float2 texcoord0 : TEXCOORD0;
				float3 normal    : NORMAL;
				float4 color     : COLOR;
				
			};

			struct v2f
			{
				float4 vertex : SV_POSITION;
				float2 uv     : TEXCOORD0;
				float3 normal : TEXCOORD1;
				float4 color  : COLOR;
			};

			struct f2g
			{
				float4 color : SV_TARGET;
			};

			void Vert(a2v i, out v2f o)
			{
				o.vertex = UnityObjectToClipPos(i.vertex);
				o.uv     = i.texcoord0;
				o.normal = mul((float3x3)UNITY_MATRIX_IT_MV, i.normal);
				o.color  = i.color * _Color;
				
			}

			void Frag(v2f i, out f2g o)
			{
				float rim = _Shift - pow(saturate(1.0f - normalize(i.normal).z), _Rim);

				o.color = tex2D(_MainTex, i.uv) * lerp(_Color1, _Color2, rim) * i.color;
			}
			ENDCG
		} // Pass
	} // SubShader

Thanks !

~be

Tags
{
    "Queue" = "Transparent"    //Set queue to sort transparencies properly
    "PreviewType" = "Sphere"
    "DisableBatching" = "True"
}
 
Pass
{
    //Use regular transparent blending
    Blend SrcAlpha OneMinusSrcAlpha

    CGPROGRAM
    #pragma vertex Vert
    #pragma fragment Frag

...

Depending on what kind of shader it is there are a few ways of going about adding transparency, but for vertex/fragment shaders you can just add the correct alpha-blending tags in the shaderlab pass before the main shader. This is quite possibly the most asked question in regards to shaders in Unity, so if you’re looking for more information you can just search for alpha-blending.