Help Needed - VBO Terrain

                Vector3 eyePosition = new Vector3(0.0f, 100.0f, 100.0f); // 4 change
 
		protected override void OnUpdateFrame(FrameEventArgs e)
		{
			if(Keyboard[Key.W])
				eyePosition.Z += 0.5f;
			if(Keyboard[Key.S])
				eyePosition.Z -= 0.5f;
			if(Keyboard[Key.D])
				eyePosition.X += 0.5f;
			if(Keyboard[Key.A])
				eyePosition.X -= 0.5f;
			if(Keyboard[Key.Q])
				eyePosition.Y += 0.5f;
			if(Keyboard[Key.Z])
				eyePosition.Y -= 0.5f;
		}
 
		protected override void OnRenderFrame(FrameEventArgs e)
		{
			GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit); // 3 change
 
			GL.MatrixMode(MatrixMode.Modelview); // 1 change
			GL.LoadIdentity();					 // 2 change
			Matrix4 modelview = Matrix4.LookAt(eyePosition, eyeTarget, Vector3.UnitY);
			GL.LoadMatrix(ref modelview);
 
			GL.Begin(BeginMode.Quads);
			GL.TexCoord2(0.0f, 1.0f); GL.Vertex2(-4.6f, -4.4f); // 5 change
                        GL.TexCoord2(1.0f, 1.0f); GL.Vertex2(4.6f, -4.4f); // 6 change
                        GL.TexCoord2(1.0f, 0.0f); GL.Vertex2(4.6f, 4.4f); // 7 change
                        GL.TexCoord2(0.0f, 0.0f); GL.Vertex2(-4.6f, 4.4f); // 8 change
			GL.End();
 
			RenderTerrain();
 
			SwapBuffers();
		}