title: glDrawElements not working in the other machine
body: <p>I'm using OpenGL with g++. This simple code works fine in my system. It draws a rectangle as expected.</p>
  
  <pre><code>GLfloat vertices[] = 
  {
      0,0,0,  //0
      0,6,0,  //1
      6,6,0,  //2
      6,0,0,  //3
  };
  GLint indices[] = {0,1,2,3};
  glColor3f(1,0,0);
  glVertexPointer (3, GL_FLOAT, 0, vertices);
  glDrawElements(GL_QUADS, 4, GL_UNSIGNED_INT, indices);
  </code></pre>
  
  <p>But in my friend's system, it gives segmentation fault.</p>
  
  <p>I changed <code>GL_UNSIGNED_INT</code> to <code>GL_INT</code>. Then at least it does not give segmentation fault but its not rendering anything.</p>
  
  <p>What can be the reason for this?</p>