Unity 3D shader example blending between two textures

Shader "BlendBetweenTwo" {

	Properties {
	    _Blend ("Blend", Range (0, 1) ) = 0.5
	    _MainTex ("Texture 1", 2D) = ""
	    _Texture2 ("Texture 2", 2D) = ""
	}

	SubShader {
	    Pass {
	        SetTexture[_MainTex]
	        SetTexture[_Texture2] {
	            ConstantColor (0,0,0, [_Blend])
	            Combine texture Lerp(constant) previous
	        }
	    }
	}

}