Errors calling certain gl-based classes

Question

Following this example code, I'm trying to use glGenFramebuffersEXT(), GL2.GL_FRAGMENT_SHADER_ARB, but I get these two types of highlighted errors wherever they are called:

The method glGenFramebuffersEXT(int, int[], int) is undefined for the type GL2

and

GL_FRAGMENT_SHADER_ARB cannot be resolved or is not a field.

Here are my following imports:

import java.awt.image.BufferedImage;
import java.io.IOException;

import javax.imageio.ImageIO;
import javax.media.opengl.GL;
import javax.media.opengl.GL2;

I have all the JOGL libraries within my build path, but does anyone possibly know or have a clue as to why I'm getting these errors?