2 errors In Checkerboard java code Please Help?

Hi Everyone

could someone please help me correct these 2 errors. This program is to create an application that demonstrates Array and Looping structures.

Code: import java.awt.*;

import java.awt.event.*;

import javax.swing.JOptionPane;

public class Checkerboard extends Frame implements ActionListener

{

//Declare the Panels that holds the Array

Panel boardPanel = new Panel();

TextArea numberArea[] = new TextArea[16];

////Declares the Panel that holds three fiels and labels

Panel buttonPanel = new Panel();

Button goBut = new Button("Go");

Label startLabel = new Label("Start");

Label stepLabel = new Label("Step");

Label stopLabel = new Label("Stop");

Panel inputPanel = new Panel();

int start=0, stop=0, step=0;

TextField startField = new TextField();

TextField stepField = new TextField();

TextField stopField = new TextField();

public Checkerboard()

{

// set layouts for frame and two panels

this.setLayout(new BorderLayout());

boardPanel.setLayout(new GridLayout(4,4));

inputPanel.setLayout(new GridLayout(2,3));

buttonPanel.setLayout(new FlowLayout(FlowLayout.LEFT));

// add components to board Panel

for (int i = 0; i < numberArea.length; i++) {

numberArea[i] = new TextArea(null, 3, 5, 3);

numberArea[i].setText(Integer.toString(i));

numberArea[i].setEditable(false);

numberArea[i].setBackground(Color.WHITE);

boardPanel.add(numberArea[i]);

}

// add components to input Panel

inputPanel.add(startField);

inputPanel.add(stepField);

inputPanel.add(stopField);

inputPanel.add(startLabel);

inputPanel.add(stepLabel);

inputPanel.add(stopLabel);

//buttonPanel Component

buttonPanel.add(goBut);

// add panels to frame

add(boardPanel, BorderLayout.NORTH);

add(inputPanel, BorderLayout.CENTER);

add(buttonPanel, BorderLayout.SOUTH);

goBut.addActionListener(this);

// overriding the windowClosing() method will allow the user to click the Close button

addWindowListener(new WindowAdapter() {

public void windowClosing(WindowEvent e) {

System.exit(0);

}

});

}// end of constructor method

public static void main(String[] args)

{

Checkerboard f = new Checkerboard();

f.setBounds(50, 100, 300, 400);

f.setTitle("Checkerboard Array");

f.setVisible(true);

}// end of main() method

public void actionPerformed(ActionEvent e)

{

String arg = e.getActionCommand();

try

{

start = Integer.parseInt(startField.getText());

step = Integer.parseInt(stepField.getText());

stop = Integer.parseInt(stopField.getText());

}catch(Exception exception)

{

return;

}

Object src = e.getSource();

for (int x = start -1; x < stop; x = step) //you need to do the -1 because the array subscript values in Java all start

//with zero, but humans use numbers starting with 1

{

//numberArea[x] = numberArea[start & start++].setBackground(Color.magenta);//..change the color for that square here

if (src == goBut)

{

if (start >= 0 && start <= 15 && start < stop) {

numberArea[x] = numberArea[start + start++].setBackground(Color.magenta);

}

else

{

JOptionPane

.showMessageDialog(

null,

"You have entered an incorrect number or a number larger than 15. Please try again",

"Error", JOptionPane.ERROR_MESSAGE);

}

if (step >= 0 && step <= 15 && start < stop) {

numberArea[x] = numberArea[step + step++].setBackground(Color.yellow);

}

}

}

}

}

Errors: C:\Users\user\Desktop\Checkerboard.java:111: incompatible types

found : void

required: java.awt.TextArea

numberArea[x] = numberArea[start + start++].setBackground(Color.magenta);

^

C:\Users\user\Desktop\Checkerboard.java:124: incompatible types

found : void

required: java.awt.TextArea

numberArea[x] = numberArea[step + step++].setBackground(Color.yellow);