Shader Problem

Hey I got an error and wondered if someone could help me with it. The error I got was: "Shader error in 'Parallax Specular Occlusion': Program 'SurfShaderInternalFunc', unable to find compatible overloaded function "tex2D(error, float2)" at line 89". Not sure what I should do to fix it.

 Shader "Parallax Specular Occlusion" {
 
 Properties {
 
     _Color ("Main Color", Color) = (1,1,1,1)
     _SpecColor ("Specular Color", Color) = (0.5, 0.5, 0.5, 1)
     _Shininess ("Shininess", Range (0.03, 1)) = 0.078125
     _Parallax ("Height", Range (0.005, 0.08)) = 0.02
     _MainTex ("Base (RGB) Gloss (A)", 2D) = "white" {}
     _SpecMap ("Specular map", 2D) = "black" {}
     _BumpMap ("Normalmap", 2D) = "bump" {}
     _ParallaxMap ("Heightmap (A)", 2D) = "black" {}
     _Occlusion ("Occlusion Map", 2D) = "white" {}
 
 }
 
 SubShader { 
 
     Tags { "RenderType"="Opaque" }
 
     LOD 600
 
 CGPROGRAM
 
 #pragma surface surf BlinnPhong
 
 #pragma target 3.0
 
 sampler2D _MainTex;
 sampler2D _BumpMap;
 sampler2D _SpecularMap;
 sampler2D _ParallaxMap;
 sampler2D _Occlusion;
 fixed4 _Color;
 half _Shininess;
 float _Parallax;
 
 struct Input {
 
     float2 uv_MainTex;
     float2 uv_BumpMap;
     float2 uv_SpecMap;
     float3 viewDir;
 };
 
  
 
 void surf (Input IN, inout SurfaceOutput o) {
 
     half h = tex2D (_ParallaxMap, IN.uv_BumpMap).w;
     float2 offset = ParallaxOffset (h, _Parallax, IN.viewDir);
     IN.uv_MainTex += offset;
     IN.uv_BumpMap += offset;
 
     fixed4 tex = tex2D(_MainTex, IN.uv_MainTex);
     fixed4 Occ = tex2D(_Occlusion, IN.uv_MainTex);
     fixed4 specTex = tex2D(_SpecMap, IN.uv_SpecMap); //This is the Line with the Error
     o.Albedo = tex.rgb * _Color.rgb * Occ.rgb;
     o.Gloss = specTex.r;
     o.Alpha = tex.a * _Color.a;
     o.Specular = _Shininess * specTex.g;
     o.Normal = UnpackNormal(tex2D(_BumpMap, IN.uv_BumpMap));
 }
 
 ENDCG
 
 }
 FallBack "Specular"
 }