Transparent/Diffuse Texture that includes fullforwardShadow

I managed to get a Diffuse fullforwardShadow Working, However I have some textures that are transparent. How could i modify this code to handle this?

 Shader "Custom/DiffuseForward" {
 Properties {
     _MainTex ("Main Texture", 2D) = "white" {}
 }
 SubShader {
     Tags { "RenderType"="Opaque" }
     LOD 200
     CGPROGRAM
     #pragma surface surf Lambert fullforwardshadows
     //#pragma target 3.0

     uniform sampler2D _MainTex;

     struct Input {
         float2 uv_MainTex;
     };

     void surf (Input IN, inout SurfaceOutput o) {
         half4 c = tex2D (_MainTex, IN.uv_MainTex);
         o.Albedo = c.rgb;
         o.Alpha = c.a;
     }
     ENDCG
 } 
 FallBack "Diffuse"
 }