The class Newfile has a red zig zaggy line underneath it, The type Newfile must implement the inherited abstract method ActionListener.actionPerformed(ActionEvent).
What does this mean?
My code ^_^' :

import java.awt.FlowLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JButton;
import javax.swing.JMenu;
import javax.swing.*;
import java.util.*;
public class tuna extends JFrame{
	private JButton load;
	private JButton save;
	private JButton newfile;
	public tuna(){
		super("Notes");
		setLayout(new FlowLayout());
		newfile = new JButton("New");
		load = new JButton("Load");
		save = new JButton("Save");
		add(newfile);
		add(load);
		add(save);
		class Newfile implements ActionListener{
			public void actionPeformed(ActionEvent e){
				JOptionPane.showMessageDialog(null, "This feature isn't available yet.");
			}
		}
	}
}

Please help anyone.

The class Newfile must implement the inherited abstract method.
Read the API doc for that interface and make sure you have correctly coded the methods it defines.