Shader not compiling

I have trouble trying to use some varying variable to pass info from the vertex shader to the fragment shader.

My modification to the CubeShaders is as follow:

varying vec2 clipdist;

uniform mat4 modelViewProjectionMatrix;

uniform vec4 clipPlane;

void main()

{

gl_Position = modelViewProjectionMatrix * vertexPosition;

normal = vertexNormal;

texCoord = vertexTexCoord;

clipdist[0] = clipPlane[0];

}

";

?

static const char* cubeFragmentShader = "

precision mediump float;

varying vec2 texCoord;

varying vec4 normal;

varying vec2 clipdist;

uniform sampler2D texSampler2D;

void main()

{

if (clipdist[0] > 50) discard;

gl_FragColor = texture2D(texSampler2D, texCoord);

}

";

The message is telling me of problems when compiling the fragment shader, without more details. The problem comes from the use of clipdist[0], If I use if (55 > 50) it works; but I can't figure what is wrong. Have also tried with a float instead of a vec2, but the problem is still there.

Can somebody help me ?

Thanks in advance

I have also