Adding ActionListeners to buttons in Java

I am trying to understand how I can print out info after clicking the button. I have tried several things but I am learning on my own. I am currently on knowing the different Listeners so help me on the adding the button Listener.

I wanted when a combobox is selected it prints out info and shows some details. I have a button but I want once the info in the combobox is selected it prints out info.

import javax.swing.*;
import java.awt.Color;
import java.awt.Component;
import java.awt.event.*;

public class ItemCheck extends JFrame{

    JComboBox PainandFeverReliever;
    JButton button1;
    JLabel lable;

    public static void main(String[] args){
        new ItemCheck();
    }

    public ItemCheck(){
        this.setSize(400,400);

        this.setLocationRelativeTo(null);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        this.setTitle("Medicine Stock");

        JPanel thePanel = new JPanel();
        JLabel label = new JLabel (" Medicine");
        label.setToolTipText("This Shows you how many medicine you have left in the store.");
        thePanel.add(label);

        String[] shows = {"","Cetaminophen" , "ephedrine","menthol"};

        PainandFeverReliever = new JComboBox(shows);
        PainandFeverReliever.addItem("Pushing Daisies");

        thePanel.add(PainandFeverReliever);

        button1 = new JButton("Results");

        ListenForButton lForButton = new ListenForButton();

        button1.addActionListener(lForButton);
        thePanel.add(button1);

        this.add(thePanel);

        this.setVisible(true);

        PainandFeverReliever.insertItemAt("diphenhydramine", 1);

        PainandFeverReliever.setMaximumRowCount(20);
    }

    private void setForeground(int hsBtoRGB) {
        // TODO Auto-generated method stub
    }

    private class ListenForButton implements ActionListener{
        public void actionPerformed(ActionEvent e){
            if(e.getSource() == button1){
            }
        }
    }
}