Am going to send you my java project, here is the first window:
import java.awt.EventQueue;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JLabel;
import java.awt.Font;
import javax.swing.SwingConstants;
import javax.swing.border.TitledBorder;
import javax.swing.border.EtchedBorder;
import java.awt.Color;
import javax.swing.border.BevelBorder;
import javax.swing.border.CompoundBorder;
import javax.swing.border.LineBorder;
import javax.swing.UIManager;
import javax.swing.border.SoftBevelBorder;
import javax.swing.border.MatteBorder;
import java.awt.GridLayout;
import javax.swing.ImageIcon;
import javax.swing.JComboBox;
import javax.swing.DefaultComboBoxModel;
import javax.swing.BoxLayout;
import java.awt.FlowLayout;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

public class PizzaOrder extends JFrame {

	private JPanel contentPane;
	private JPanel ToppingSelect;
	private JTextField NumPizza;
	private JTextField NumTopping;
	private JTextField NumBreuvage;

	/**
	 * Launch the application.
	 */
	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				try {
					PizzaOrder frame = new PizzaOrder();
					frame.setVisible(true);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		});
	}

	/**
	 * Create the frame.
	 */
	public PizzaOrder() {
		setTitle("Order");
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setBounds(100, 100, 630, 689);
		contentPane = new JPanel();
		contentPane.setBackground(new Color(255, 147, 0));
		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));

		setContentPane(contentPane);
		contentPane.setLayout(null);
		
		JPanel Menu = new JPanel();
		Menu.setBackground(new Color(255, 147, 0));
		Menu.setBorder(new TitledBorder(new LineBorder(new Color(0, 0, 0)), "Menu", TitledBorder.LEADING, TitledBorder.TOP, null, new Color(0, 0, 0)));
		Menu.setBounds(6, 6, 618, 158);
		contentPane.add(Menu);
		Menu.setLayout(new GridLayout(0, 3, 0, 0));
		
		JPanel PizzaPrice = new JPanel();
		PizzaPrice.setBackground(new Color(255, 147, 0));
		PizzaPrice.setBorder(new TitledBorder(new EtchedBorder(EtchedBorder.LOWERED, null, null), "Pizza", TitledBorder.LEADING, TitledBorder.TOP, null, null));
		Menu.add(PizzaPrice);
		PizzaPrice.setLayout(null);
		
		JLabel PetitPizza = new JLabel("Petit: 6.79$");
		PetitPizza.setBounds(17, 21, 72, 16);
		PizzaPrice.add(PetitPizza);
		
		JLabel MoyenPizza = new JLabel("Moyen: 8.29$");
		MoyenPizza.setBounds(17, 40, 85, 16);
		PizzaPrice.add(MoyenPizza);
		
		JLabel LargePizza = new JLabel("Large: 9.49$");
		LargePizza.setBounds(17, 59, 85, 16);
		PizzaPrice.add(LargePizza);
		
		JLabel ExtraLargePizza = new JLabel("Extra Large: 10.29$");
		ExtraLargePizza.setBounds(17, 78, 127, 16);
		PizzaPrice.add(ExtraLargePizza);
		
		JLabel FetePizza = new JLabel("Fete: 15.99$");
		FetePizza.setBounds(17, 97, 93, 16);
		PizzaPrice.add(FetePizza);
		
		JPanel ToppingPrice = new JPanel();
		ToppingPrice.setBackground(new Color(255, 147, 0));
		ToppingPrice.setLayout(null);
		ToppingPrice.setBorder(new TitledBorder(new EtchedBorder(EtchedBorder.LOWERED, null, null), "Toppings", TitledBorder.LEADING, TitledBorder.TOP, null, new Color(0, 0, 0)));
		Menu.add(ToppingPrice);
		
		JLabel Petittopping = new JLabel("Petit: 1.20$");
		Petittopping.setBounds(17, 21, 72, 16);
		ToppingPrice.add(Petittopping);
		
		JLabel Moyentopping = new JLabel("Moyen: 1.40$");
		Moyentopping.setBounds(17, 40, 85, 16);
		ToppingPrice.add(Moyentopping);
		
		JLabel Largetopping = new JLabel("Large: 1.60$");
		Largetopping.setBounds(17, 59, 85, 16);
		ToppingPrice.add(Largetopping);
		
		JLabel ExtraLargetopping = new JLabel("Extra Large: 1.80$");
		ExtraLargetopping.setBounds(17, 78, 127, 16);
		ToppingPrice.add(ExtraLargetopping);
		
		JLabel Fetetopping = new JLabel("Fete: 2.30$");
		Fetetopping.setBounds(17, 97, 93, 16);
		ToppingPrice.add(Fetetopping);
		
		JPanel BreuvagePrice = new JPanel();
		BreuvagePrice.setBackground(new Color(255, 147, 0));
		BreuvagePrice.setLayout(null);
		BreuvagePrice.setBorder(new TitledBorder(new EtchedBorder(EtchedBorder.LOWERED, null, null), "Breuvages", TitledBorder.LEADING, TitledBorder.TOP, null, new Color(0, 0, 0)));
		Menu.add(BreuvagePrice);
		
		JLabel Pop = new JLabel("Pop: 1.10$");
		Pop.setBounds(17, 21, 72, 16);
		BreuvagePrice.add(Pop);
		
		JLabel Jus = new JLabel("Jus: 1.35$");
		Jus.setBounds(17, 40, 85, 16);
		BreuvagePrice.add(Jus);
		
		JLabel Eau = new JLabel("Eau: 1.00$");
		Eau.setBounds(17, 59, 85, 16);
		BreuvagePrice.add(Eau);
		
		JPanel PizzaSelect = new JPanel();
		PizzaSelect.setBorder(new SoftBevelBorder(BevelBorder.LOWERED, null, null, null, null));
		PizzaSelect.setBackground(new Color(255, 147, 0));
		PizzaSelect.setBounds(16, 187, 350, 300);
		contentPane.add(PizzaSelect);
		PizzaSelect.setLayout(null);
		
		JComboBox ChoixPizza = new JComboBox();
		ChoixPizza.setBounds(44, 8, 126, 27);
		ChoixPizza.setModel(new DefaultComboBoxModel(new String[] {"Petit", "Moyen", "Large", "Extra Large", "Fete"}));
		ChoixPizza.setMaximumRowCount(5);
		PizzaSelect.add(ChoixPizza);
		
		NumPizza = new JTextField();
		NumPizza.setBounds(175, 8, 130, 26);
		PizzaSelect.add(NumPizza);
		NumPizza.setColumns(10);
		
		JLabel PizzaIcon = new JLabel("");
		PizzaIcon.setBounds(6, 6, 350, 279);
		PizzaSelect.add(PizzaIcon);
		PizzaIcon.setIcon(new ImageIcon(PizzaOrder.class.getResource("/Image/PizzaImage.png")));
		
		JPanel ToppingSelect;
		ToppingSelect = new JPanel();
		ToppingSelect.setBorder(new SoftBevelBorder(BevelBorder.LOWERED, null, null, null, null));
		ToppingSelect.setBackground(new Color(255, 147, 0));
		ToppingSelect.setBounds(400, 187, 208, 129);
		contentPane.add(ToppingSelect);
		ToppingSelect.setLayout(null);
		
		JComboBox ChoixTopping = new JComboBox();
		ChoixTopping.setBounds(41, 8, 126, 27);
		ChoixTopping.setModel(new DefaultComboBoxModel(new String[] {"Petit", "Moyen", "Large", "Extra Large", "Fete"}));
		ChoixTopping.setMaximumRowCount(5);
		ToppingSelect.add(ChoixTopping);
		
		NumTopping = new JTextField();
		NumTopping.setBounds(39, 40, 130, 26);
		NumTopping.setColumns(10);
		ToppingSelect.add(NumTopping);
		
		JLabel ToppingIcon = new JLabel("");
		ToppingIcon.setIcon(new ImageIcon(PizzaOrder.class.getResource("/Image/ToppingImage.png")));
		ToppingIcon.setBounds(6, 8, 208, 109);
		ToppingSelect.add(ToppingIcon);
		
		JPanel BreuvageSelect = new JPanel();
		BreuvageSelect.setBorder(new SoftBevelBorder(BevelBorder.LOWERED, null, null, null, null));
		BreuvageSelect.setBackground(new Color(255, 147, 0));
		BreuvageSelect.setBounds(400, 358, 208, 129);
		contentPane.add(BreuvageSelect);
		BreuvageSelect.setLayout(null);
		
		JComboBox ChoixBreuvage = new JComboBox();
		ChoixBreuvage.setBounds(64, 8, 79, 27);
		ChoixBreuvage.setModel(new DefaultComboBoxModel(new String[] {"Pop", "Jus", "Eau"}));
		ChoixBreuvage.setMaximumRowCount(3);
		BreuvageSelect.add(ChoixBreuvage);
		
		NumBreuvage = new JTextField();
		NumBreuvage.setBounds(39, 40, 130, 26);
		NumBreuvage.setColumns(10);
		BreuvageSelect.add(NumBreuvage);
		
		JLabel BreuvageIcon = new JLabel("");
		BreuvageIcon.setIcon(new ImageIcon(PizzaOrder.class.getResource("/Image/BreuvageImage.png")));
		BreuvageIcon.setBounds(0, 0, 209, 129);
		BreuvageSelect.add(BreuvageIcon);
		
		JButton Quitter = new JButton("Quitter");
		Quitter.setBounds(33, 552, 160, 50);
		contentPane.add(Quitter);
		
		JButton Ajouter = new JButton("Ajouter");
		Ajouter.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
			}
		});
		Ajouter.setBounds(234, 552, 160, 50);
		contentPane.add(Ajouter);
		
		JButton Payer = new JButton("Payer");
		Payer.setBounds(431, 552, 160, 50);
		contentPane.add(Payer);
		
	}
}


And below is the second window:


import java.awt.EventQueue;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JLabel;
import javax.swing.border.TitledBorder;
import javax.swing.ImageIcon;

public class Receipt extends JFrame {

	private JPanel contentPane;

	/**
	 * Launch the application.
	 */
	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				try {
					Receipt frame = new Receipt();
					frame.setVisible(true);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		});
	}

	/**
	 * Create the frame.
	 */
	public Receipt() {
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setBounds(100, 100, 253, 403);
		contentPane = new JPanel();
		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));

		setContentPane(contentPane);
		contentPane.setLayout(null);
		
		JPanel panel = new JPanel();
		panel.setBounds(6, 6, 241, 363);
		panel.setBorder(null);
		contentPane.add(panel);
		panel.setLayout(null);
		
		JLabel Order = new JLabel("Order:");
		Order.setBounds(21, 31, 61, 16);
		panel.add(Order);
		
		JLabel Total = new JLabel("Total:");
		Total.setBounds(43, 275, 61, 16);
		panel.add(Total);
		
		JLabel ReceiptIcon = new JLabel("");
		ReceiptIcon.setBounds(0, 5, 241, 363);
		ReceiptIcon.setIcon(new ImageIcon(Receipt.class.getResource("/Image/ReceiptImage.png")));
		panel.add(ReceiptIcon);
	}

}

Modify my java code so that When the button Ajouter is clicked, it will add the prices of whatever is chosen for ChoixPizza*NumPizza, ChoixTopping*NumTopping and ChoixBreuvage*NumBreuvage to the total, once the button Payer is clicked, the window Receipt will pop up and show what was added and then show the total under the order with 13% tax


These are the prices:
Pizza Prices; 
Small: $6.79 
Medium: $8.29 
Large: 9.49$ 
Extra Large: 10.29 $
Fete: 15.99 $
Topping;
Small: $1.20 
Medium: $1.40 
Large: $1.60 
Extra Large: $1.80 
Fete: $2.30 
Breuvages;
Pop 1,10 $ 
Juice 1,35 $
Eau: 1,00$

Show me the new code in a way I can copy and paste it in java