Add Shadows to Shader

Anyone know how I could add support for runtime shadows(unity pro) to this shaders? Thanks!

 Shader "Terrain/AlphaBlended" {
 Properties {
     _MainTex ("Base (RGB)", 2D) = "white" {}
     _DetailTex ("Detail (RGB)", 2D) = "white" {}
     _LowTex ("Low (RGB)", 2D) = "white" {}
     _BlendMap ("BlendMap (RGBA)", 2D) = "white" {}
     _LightMap ("LightMap (RGB)", 2D) = "white" {}
 }
 SubShader {
     Pass {
         Material {
             Diffuse (1,1,1,1)
             Ambient (1,1,1,1)
         }
         Lighting On
         BindChannels {
               Bind "vertex", vertex
                 Bind "color", color
                 Bind "texcoord", texcoord

         }

         
         SetTexture [_BlendMap] {
             Combine texture
         }
         
         SetTexture [_DetailTex] {
             Combine texture * previous
         }
         


         SetTexture [_MainTex] {
             Combine previous lerp (previous) texture
         }
         
         SetTexture [_LightMap] {
             Combine previous * texture
         }
         
         
     }
 } 
 FallBack "Diffuse", 1

}