need help with java program

[twin2003]

need help with inventory part 5 here is what I have to do
Modify the Inventory Program by adding a button to the GUI that allows the user to move to the first item, the previous item, the next item, and the last item in the inventory. If the first item is displayed and the user clicks on the Previous button, the last item should display. If the last item is displayed and the user clicks on the Next button, the first item
should display. the GUI using Java graphics classes.
• Add a company logo to
here is what i have so far

// created by Nicholas Baatz on July 24,2007
  import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;



public class Inventory2
{
//main method begins execution of java application
public static void main(final String args[])
{

int i; // varialbe for looping
double total = 0; // variable for total inventory
final int dispProd = 0; // variable for actionEvents

// Instantiate a product object
final ProductAdd[] nwProduct = new ProductAdd[5];
// Instantiate objects for the array
for (i=0; i<5; i++)
{
nwProduct[0] = new ProductAdd("Paper", 101, 10, 1.00, "Box");
nwProduct[1] = new ProductAdd("Pen", 102, 10, 0.75, "Pack");
nwProduct[2] = new ProductAdd("Pencil", 103, 10, 0.50, "Pack");
nwProduct[3] = new ProductAdd("Staples", 104, 10, 1.00, "Box");
nwProduct[4] = new ProductAdd("Clip Board", 105, 10, 3.00, "Two Pack");
}



for (i=0; i<5; i++)
total += nwProduct.length; // calculate total inventory cost



final JButton firstBtn = new JButton("First"); // first button
final JButton prevBtn = new JButton("Previous"); // previous button
final JButton nextBtn = new JButton("Next"); // next button
final JButton lastBtn = new JButton("Last"); // last button
final JLabel label; // logo
final JTextArea textArea; // text area for product list
final JPanel buttonJPanel; // panel to hold buttons

//JLabel constructor for logo
Icon logo = new ImageIcon("C:/logo.jpg"); // load logo
label = new JLabel(logo); // create logo label
label.setToolTipText("Company Logo"); // create tooltip


buttonJPanel = new JPanel(); // set up panel
buttonJPanel.setLayout( new GridLayout(1, 4)); //set layout
// add buttons to buttonPanel
buttonJPanel.add(firstBtn);
buttonJPanel.add(prevBtn);
buttonJPanel.add(nextBtn);
buttonJPanel.add(lastBtn);


textArea = new JTextArea(nwProduct[3]+"\n"); // create textArea for product display

// add total inventory value to GUI
textArea.append("\nTotal value of Inventory "+new java.text.DecimalFormat("$0.00").format(total)+"\n\n");
textArea.setEditable(false); // make text uneditable in main display
JFrame invFrame = new JFrame(); // create JFrame container
invFrame.setLayout(new BorderLayout()); // set layout
invFrame.getContentPane().add(new JScrollPane(textArea), BorderLayout.CENTER); // add textArea to JFrame
invFrame.getContentPane().add(buttonJPanel, BorderLayout.SOUTH); // add buttons to JFrame
invFrame.getContentPane().add(label, BorderLayout.NORTH); // add logo to JFrame
invFrame.setTitle("Office Min Inventory"); // set JFrame title
invFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // termination command
//invFrame.pack();
invFrame.setSize(400, 400); // set size of JPanel
invFrame.setLocationRelativeTo(null); // set screem location
invFrame.setVisible(true); // display window



// assign actionListener and actionEvent for each button
firstBtn.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent ae)
{
textArea.setText(nwProduct[0]+"\n");
} // end firstBtn actionEvent

}); // end firstBtn actionListener
textArea.setText(nwProduct[4]+"n");

// prevBtn.addActionListener(new ActionListener()
// {
// public void actionPerformed(ActionEvent ae)
// {
// dispProd = (nwProduct.length+dispProd-1) % nwProduct.length;
// textArea.setText(nwProduct.display(dispProd)+"\n");
// } // end prevBtn actionEvent
// }); // end prevBtn actionListener





} // end main

} // end class Inventory2

class Product
{
protected String prodName; // name of product
protected int itmNumber; // item number
protected int units; // number of units
protected double price; // price of each unit
protected double value; // value of total units


public Product(String name, int number, int unit, double each) // Constructor for class Product
{
prodName = name;
itmNumber = number;
units = unit;
price = each;

} // end constructor

public void setProdName(String name) // method to set product name
{
prodName = name;
}

public String getProdName() // method to get product name
{
return prodName;
}

public void setItmNumber(int number) // method to set item number
{
itmNumber = number;
}

public int getItmNumber() // method to get item number
{
return itmNumber;
}

public void setUnits(int unit) // method to set number of units
{
units = unit;
}

public int getUnits() // method to get number of units
{
return units;
}

public void setPrice(double each) // method to set price
{
price = each;
}

public double getPrice() // method to get price
{
return price;
}

public double calcValue() // method to set value
{
return units * price;
}



} // end class Product



class ProductAdd extends Product
{
private String feature; // variable for added feature


public ProductAdd(String name, int number, int unit, double each, String addFeat)
{
// call to superclass Product constructor
super(name, number, unit, each);

feature = addFeat;
}// end constructor

public void setFeature(String addFeat) // method to set added feature
{
feature = addFeat;
}

public String getFeature() // method to get added feature
{
return feature;
}

public double calcValueRstk() // method to set value and add restock fee
{
return units * price * 0.05;
}

public String toString()
{
return String.format("Product: %s\nItem Number: %d\nIn Stock: %d\nPrice: $%.2f\nType: %s\nTotal Value of Stock: $%.2f\nRestock Cost: $%.2f\n\n\n",
getProdName(), getItmNumber(), getUnits(), getPrice(), getFeature(), calcValue(), calcValueRstk());
}


} // end class ProductAdd

This code compiles and runds but cant get all my buttons to work any help would be nice thxs

[r035198x]

You haven't been specific enough with your problem. Which button doesn't work? What is it doing now vs what you want it to do?