private void exitOnGLError(String errorMessage) {
		int errorValue = GL11.glGetError();
		
		if (errorValue != GL11.GL_NO_ERROR) {
			String errorString = GLU.gluErrorString(errorValue);
			System.err.println("ERROR - " + errorMessage + ": " + errorString);
			
			if (Display.isCreated()) Display.destroy();
			System.exit(-1);
		}
	}