Add transparency to shader

I found this shader someone wrote and i don’t think it has transparency written in it. How can I add transparency to this shader code?

Shader "Custom/SpriteGradient" {
Properties {
     [PerRendererData] _MainTex ("Sprite Texture", 2D) = "white" {}
     _Color ("Left Color", Color) = (1,1,1,1)
     _Color2 ("Right Color", Color) = (1,1,1,1)
     _Scale ("Scale", Float) = 1
   
// these six unused properties are required when a shader
// is used in the UI system, or you get a warning.
// look to UI-Default.shader to see these.
_StencilComp ("Stencil Comparison", Float) = 8
_Stencil ("Stencil ID", Float) = 0
_StencilOp ("Stencil Operation", Float) = 0
_StencilWriteMask ("Stencil Write Mask", Float) = 255
_StencilReadMask ("Stencil Read Mask", Float) = 255
_ColorMask ("Color Mask", Float) = 15
// see for example
// http://answers.unity3d.com/questions/980924/ui-mask-with-shader.html
}

SubShader {
     Tags {"Queue"="Background"  "IgnoreProjector"="True"}
     LOD 100

     ZWrite Off

     Pass {
          Blend SrcAlpha OneMinusSrcAlpha
         CGPROGRAM
         #pragma vertex vert
         #pragma fragment frag
         #include "UnityCG.cginc"

         fixed4 _Color;
         fixed4 _Color2;
         fixed  _Scale;

         struct v2f {
             float4 pos : SV_POSITION;
             fixed4 col : COLOR;
         };

         v2f vert (appdata_full v)
         {
             v2f o;
             o.pos = mul (UNITY_MATRIX_MVP, v.vertex);
             o.col = lerp(_Color,_Color2, v.texcoord.x );
             return o;
         }
      

         float4 frag (v2f i) : COLOR {
             float4 c = i.col;
             c.a = 1;
             return c;
         }
             ENDCG
         }
     }
}

Add

Blend SrcAlpha OneMinusSrcAlpha

between

Pass {

and

CGPROGRAM

thanks, i tried it but still no alpha effect =(