Multiple lights PHONG

I’m trying to implement the shaders of this tutorial, but all I get is a black screen. With my old shaders everything is rendering. Could someone give me some advise how to implement it?

I tried adding lights, but that made no difference:


	     glEnable(GL_LIGHTING);
	     glEnable(GL_LIGHT0);
	     glEnable(GL_NORMALIZE);
	     
	     // Light model parameters:
	     // -------------------------------------------
	     
	     FloatBuffer lmKa = BufferUtil.asFloatBuffer(0.0f, 0.0f, 0.0f, 0.0f);
	     lmKa.flip();
	     glLightModel(GL_LIGHT_MODEL_AMBIENT, lmKa);
	     
	     glLightModelf(GL_LIGHT_MODEL_LOCAL_VIEWER, 1.0f);
	     glLightModelf(GL_LIGHT_MODEL_TWO_SIDE, 0.0f);
	     
	     // -------------------------------------------
	     // Spotlight Attenuation
	     
	     FloatBuffer spot_direction = BufferUtil.asFloatBuffer(1.0f, -1.0f, -1.0f, 0f);
	     spot_direction.flip();
	     int spot_exponent = 30;
	     int spot_cutoff = 180;
	     
	     glLight(GL_LIGHT0, GL_SPOT_DIRECTION, spot_direction);
	     glLighti(GL_LIGHT0, GL_SPOT_EXPONENT, spot_exponent);
	     glLighti(GL_LIGHT0, GL_SPOT_CUTOFF, spot_cutoff);
	    
	     float Kc = 1.0f;
	     float Kl = 0.0f;
	     float Kq = 0.0f;
	     
	     glLightf(GL_LIGHT0, GL_CONSTANT_ATTENUATION,Kc);
	     glLightf(GL_LIGHT0, GL_LINEAR_ATTENUATION, Kl);
	     glLightf(GL_LIGHT0, GL_QUADRATIC_ATTENUATION, Kq);
	     
	     
	     // ------------------------------------------- 
	     // Lighting parameters:

	     FloatBuffer light_pos = BufferUtil.asFloatBuffer(0.0f, 5.0f, 5.0f, 1.0f);
	     FloatBuffer light_Ka  = BufferUtil.asFloatBuffer(1.0f, 0.5f, 0.5f, 1.0f);
	     FloatBuffer light_Kd  = BufferUtil.asFloatBuffer(1.0f, 0.1f, 0.1f, 1.0f);
	     FloatBuffer light_Ks  = BufferUtil.asFloatBuffer(1.0f, 1.0f, 1.0f, 1.0f);
	     light_pos.flip();
	     light_Ka.flip();
	     light_Kd.flip();
	     light_Ks.flip();
	     
	     glLight(GL_LIGHT0, GL_POSITION, light_pos);
	     glLight(GL_LIGHT0, GL_AMBIENT, light_Ka);
	     glLight(GL_LIGHT0, GL_DIFFUSE, light_Kd);
	     glLight(GL_LIGHT0, GL_SPECULAR, light_Ks);

	     // -------------------------------------------
	     // Material parameters:

	     FloatBuffer material_Ka = BufferUtil.asFloatBuffer(0.5f, 0.0f, 0.0f, 1.0f);
	     FloatBuffer material_Kd = BufferUtil.asFloatBuffer(0.4f, 0.4f, 0.5f, 1.0f);
	     FloatBuffer material_Ks = BufferUtil.asFloatBuffer(0.8f, 0.8f, 0.0f, 1.0f);
	     FloatBuffer material_Ke = BufferUtil.asFloatBuffer(0.1f, 0.0f, 0.0f, 0.0f);
	     material_Ka.flip();
	     material_Kd.flip();
	     material_Ks.flip();
	     material_Ke.flip();
	     float material_Se = 20.0f;

	     glMaterial(GL_FRONT_AND_BACK, GL_AMBIENT, material_Ka);
	     glMaterial(GL_FRONT_AND_BACK, GL_DIFFUSE, material_Kd);
	     glMaterial(GL_FRONT_AND_BACK, GL_SPECULAR, material_Ks);
	     glMaterial(GL_FRONT_AND_BACK, GL_EMISSION, material_Ke);
	     glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, material_Se);