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

  public class Program5 extends JFrame
  {
     public Program5()
     {
     
        final int windowWidth = 350;
        final int windowHeight = 275;
     
     
        setTitle("Theatre Revenue ");
        setSize(windowWidth, windowHeight);
        JButton button = new JButton("Calculate ");
        button.addActionListener(new buttonListener());
        JTextField adultTicketPriceTextField;
        adultTicketPriceTextField = new JTextField(20);
        JTextField adultTicketSoldTextField;
        adultTicketSoldTextField = new JTextField(20);
        JTextField childTicketPriceTextField;
        childTicketPriceTextField = new JTextField(20);
        JTextField childTicketSoldTextField;
        childTicketSoldTextField = new JTextField(20);
        JLabel adultPrice;
        adultPrice = new JLabel("Adult Ticket Price ");
        JLabel adultSales;
        adultSales = new JLabel ("Adult Tickets Sold ");
        JLabel childPrice;
        childPrice = new JLabel ("Child Ticket Price ");
        JLabel childSales;
        childSales = new JLabel ("Child Tickets Sold ");
        JLabel spacer;
        spacer = new JLabel ("  ");
        JPanel panel1 = new JPanel();
        panel1.add(adultPrice);
        panel1.add(adultTicketPriceTextField);
        panel1.add(adultSales);
        panel1.add(adultTicketSoldTextField);
        panel1.add(childPrice);
        panel1.add(childTicketPriceTextField);
        panel1.add(childSales);
        panel1.add(childTicketSoldTextField);
        panel1.add(spacer);
        panel1.add(button);
        add(panel1);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
     }
     private class buttonListener implements ActionListener
     {
        public void actionPerformed(ActionEvent e)
        {
           String adultTickets;
           double adultTicketsNum;
           String adultSales;
           double adultSalesNum;
           String childTickets;
           double childTicketsNum;
           String childSales;
           double childSalesNum;
           double adultGross;
           double adultNet;
           double childGross;
           double childNet;
           double totalGross;
           double totalNet;
           double constant = 0.20;
       
       
           adultTickets = adultTicketPriceTextField.getText();
           adultSales = adultTicketSoldTextField.getText();
           childTickets = childTicketPriceTextField.getText();
           childSales = childTicketSoldTextField.getText();
       
           adultTicketsNum = Double.parseDouble(adultTickets);
           adultSalesNum = Double.parseDouble(adultSales);
           childTicketsNum = Double.parseDouble(childTickets);
           childSalesNum = Double.parseDouble(childSales);
       
           adultGross = adultTicketsNum * adultSalesNum;
           adultNet = adultGross * constant;
           childGross = childTicketsNum * childSalesNum;
           childNet = childGross * constant;
           totalGross = adultGross + childGross;
           totalNet = adultNet + childNet;
       
       
           JOptionPane.showMessageDialog(null, "The Gross for Adult tickets was " + adultGross +
              " The Net for Adult Tickets was " + adultNet + " The Gross for Children Tickets was " +
              childGross + " The Net for Child Tickets was " + childNet + " The Total Gross was " +
              totalGross + " The Total Net was " + totalNet);
        }
     }

  }

----jGRASP exec: javac -g Program5.java

Program5.java:72: error: cannot find symbol
           adultTickets = adultTicketPriceTextField.getText();
                          ^
 symbol:   variable adultTicketPriceTextField
 location: class Program5.buttonListener
Program5.java:73: error: cannot find symbol
           adultSales = adultTicketSoldTextField.getText();
                        ^
 symbol:   variable adultTicketSoldTextField
 location: class Program5.buttonListener
Program5.java:74: error: cannot find symbol
           childTickets = childTicketPriceTextField.getText();
                          ^
 symbol:   variable childTicketPriceTextField
 location: class Program5.buttonListener
Program5.java:75: error: cannot find symbol
           childSales = childTicketSoldTextField.getText();
                        ^
 symbol:   variable childTicketSoldTextField
 location: class Program5.buttonListener
4 errors

----jGRASP wedge2: exit code for process is 1.
----jGRASP: operation complete.