OpenGLES 2.0 Phong shader strange result, makes my object transparent when texture is enabled!

I've been stuck for several days now, trying to make my shader working properly. The problem is that when I'm not attaching a texture on my object, I multiply the ambient by the light color and I get a dark object when no light, and illuminated properly when a light source is activated.

The problem is that when I attach a texture and multiply it by ambient and light color I get a transparent object that shows up only when a light source is activated, and you can even see through the object while it is illuminated!

I've been trying several codes snippets from the internet but I always get the same result. What I'm doing wrong here? I'm desperate...

The application is developed on Android.

Here is my Vertex Shader:

uniform mat4 uMVPMatrix;
uniform mat4 normalMatrix;

// eye pos
uniform vec3 eyePos;

// position and normal of the vertices
attribute vec4 aPosition;
attribute vec3 aNormal; 

// texture variables
uniform float hasTexture;
varying float tex;
attribute vec2 textureCoord;
varying vec2 tCoord;

// lighting
uniform vec4 lightPos;
uniform vec4 lightColor;

// material
uniform vec4 matAmbient;
uniform vec4 matDiffuse;
uniform vec4 matSpecular;
uniform float matShininess;

// normals to pass on
varying vec3 vNormal;
varying vec3 EyespaceNormal;

varying vec3 lightDir, eyeVec;

void main() {
    // pass on texture variables
    tex = hasTexture;
    tCoord = textureCoord;

    // normal
    EyespaceNormal = vec3(normalMatrix * vec4(aNormal, 1.0));

    // the vertex position
    vec4 position = uMVPMatrix * aPosition; 

    // light dir
    lightDir = lightPos.xyz - position.xyz;
    eyeVec = -position.xyz;

    gl_Position = uMVPMatrix * aPosition; 
}

And here is my Fragment shader:

precision mediump float;

// texture variables
uniform sampler2D texture1; // color texture

varying float tex;
varying vec2 tCoord;

varying vec3 vNormal;
varying vec3 EyespaceNormal;

// light
uniform vec4 lightPos;
uniform开发者_运维问答 vec4 lightColor;

// material
uniform vec4 matAmbient;
uniform vec4 matDiffuse;
uniform vec4 matSpecular;
uniform float matShininess;

// eye pos
uniform vec3 eyePos;

// from vertex s
varying vec3 lightDir, eyeVec;

void main() {

    vec4 b = lightColor;
    vec4 c = matAmbient;
    vec4 d = matDiffuse;
    vec4 e = matSpecular;
    vec3 g = eyePos;
    float f = matShininess;

    vec3 N = normalize(EyespaceNormal);
    vec3 E = normalize(eyeVec); 

    vec3 L = normalize(lightDir);

    // Reflect the vector. Use this or reflect(incidentV, N);
    vec3 reflectV = reflect(-L, N);

    // Get lighting terms
    vec4 ambientTerm;
    if (tex >= 1.0) {
        ambientTerm = texture2D(texture1, tCoord);
    }
    else
        ambientTerm = matAmbient * lightColor;

    vec4 diffuseTerm = matDiffuse * max(dot(N, L), 0.0);
    vec4 specularTerm = matSpecular * pow(max(dot(reflectV, E), 0.0), matShininess);

    gl_FragColor =  ambientTerm * diffuseTerm + specularTerm;
}

Thanks in advance.

OK I found it, thanks to JPD002, I was revising the shader again, and I found out that it has to be

vec4 diffuseTerm = matDiffuse * max(dot(N, L), 0.0);
vec4 specularTerm = matSpecular * pow(max(dot(reflectV, E), 1.0), matShininess);

Thanks JDP002, it is always good to have 4 eyes on code rather than 2 =D