Java - ItemListener for JCheckBox doesn't work

Java - ItemListener for JCheckBox doesn't work

:)
I'm just a beginner and I'm having a problem with implementing an item
listener as an inner class.
What I want to happen is that if someone selects the checkbox t1, the text
above it, written in the TextArea txtTop, becomes bold.
However, Eclipse tells me that there are multiple problems with my listener.
It wants me to declare t1 and txtTop as final.
It wants me to not make the listener class private.
It doesn't find the listener anyway. The line t1.addItemListener(new
cl()); doesn't work.
So yeah, I don't know what to do. Hopefully one of you can help me out! :)
Here is the code:
import java.awt.BorderLayout;
public class WindowBuilderTest extends JFrame
{
private JPanel contentPane;
//Launch the application.
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
try
{
WindowBuilderTest frame = new WindowBuilderTest();
frame.setVisible(true);
} catch (Exception e)
{
e.printStackTrace();
}
}
});
}
// Creating Frame
public WindowBuilderTest()
{
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 1280, 720 );
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
setContentPane(contentPane);
contentPane.setLayout(null);
// Create Font
Font headfont = new Font("Serif", Font.PLAIN, 15);
// Role Headlines
final JTextArea txtTop = new JTextArea();
txtTop.setEditable(false);
txtTop.setText("TOP");
txtTop.setBounds(180, 95, 32, 23);
txtTop.setFont(headfont);
contentPane.add(txtTop);
JTextArea txtMid = new JTextArea();
txtMid.setEditable(false);
txtMid.setText("MID");
txtMid.setBounds(252, 95, 32, 23);
contentPane.add(txtMid);
JTextArea txtJng = new JTextArea();
txtJng.setEditable(false);
txtJng.setText("JNG");
txtJng.setBounds(320, 95, 32, 23);
contentPane.add(txtJng);
JTextArea txtAdc = new JTextArea();
txtAdc.setEditable(false);
txtAdc.setText("ADC");
txtAdc.setBounds(389, 95, 32, 23);
contentPane.add(txtAdc);
JTextArea txtSup = new JTextArea();
txtSup.setEditable(false);
txtSup.setText("SUP");
txtSup.setBounds(453, 95, 32, 23);
contentPane.add(txtSup);
// Checkbox 1st row
final JCheckBox t1 = new JCheckBox("");
t1.setBounds(183, 143, 23, 23);
t1.addItemListener(new cl());
contentPane.add(t1);
JCheckBox m1 = new JCheckBox("");
m1.setBounds(255, 143, 23, 23);
contentPane.add(m1);
JCheckBox j1 = new JCheckBox("");
j1.setBounds(322, 143, 23, 23);
contentPane.add(j1);
JCheckBox a1 = new JCheckBox("");
a1.setBounds(393, 143, 23, 23);
contentPane.add(a1);
JCheckBox s1 = new JCheckBox("");
s1.setBounds(457, 143, 23, 23);
contentPane.add(s1);
class cl implements ItemListener
{
@Override
public void itemStateChanged(ItemEvent e)
{
if(t1.isSelected())
{
//Font headfont = txtTop.getFont().deriveFont(Font.BOLD, 40);
//txtTop.setFont(headfont);
System.out.println("HURRA!");
}
else
{
//Font headfont = txtTop.getFont().deriveFont(Font.PLAIN,
40);
//txtTop.setFont(headfont);
System.out.println("JUHU!");
}
}
}
}
}