[solved] glNormal

I am trying to put some light on my square. But I don't know how to use glNormal. I found this: http://www.gamedev.net/community/forums/topic.asp?topic_id=513422 Now I know why. But not how. How do I use it when I want sharp edges? Here is my square:

  // Front
  glVertex3f(-1.0f,-1.0f, 1.0f);
  glVertex3f(-1.0f, 1.0f, 1.0f);
  glVertex3f( 1.0f, 1.0f, 1.0f);
  glVertex3f( 1.0f,-1.0f, 1.0f);


  // Left
  glVertex3f(-1.0f,-1.0f,-1.0f);
  glVertex3f(-1.0f, 1.0f,-1.0f);
  glVertex3f(-1.0f, 1.0f, 1.0f);
  glVertex3f(-1.0f,-1.0f, 1.0f);


  // Back
  glVertex3f( 1.0f,-1.0f,-1.0f);
  glVertex3f( 1.0f, 1.0f,-1.0f);
  glVertex3f(-1.0f, 1.0f,-1.0f);
  glVertex3f(-1.0f,-1.0f,-1.0f);


  // Right
  glVertex3f( 1.0f,-1.0f, 1.0f);
  glVertex3f( 1.0f, 1.0f, 1.0f);
  glVertex3f( 1.0f, 1.0f,-1.0f);
  glVertex3f( 1.0f,-1.0f,-1.0f);


  // Top
  glVertex3f(-1.0f, 1.0f, 1.0f);
  glVertex3f(-1.0f, 1.0f,-1.0f);
  glVertex3f( 1.0f, 1.0f,-1.0f);
  glVertex3f( 1.0f, 1.0f, 1.0f);


  // Bottom
  glVertex3f(-1.0f,-1.0f,-1.0f);
  glVertex3f(-1.0f,-1.0f, 1.0f);
  glVertex3f( 1.0f,-1.0f, 1.0f);
  glVertex3f( 1.0f,-1.0f,-1.0f);

Could somebody please tell me how I use glNormal() on that? [Edited by - Phille on January 6, 2009 9:18:53 AM]