A msg box is displayed when textfield is empty or wrong entry

Question

i put textfield in matrix on a frame know i want that when i press enter then a msg box is displayed if any text field is empty or wrong entry for example i just want to enter integer in text field i tried the following one but if i press enter without putting any entry or wrong entry it generate exceptions
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class NumericVerifier
public static void main(String args[])
JFrame frame = new JFrame("Numeric Verifier");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel1 = new JPanel(new BorderLayout());
JLabel label1 = new JLabel("Numeric-only");
JTextField textField1 = new JTextField();
panel1.add(label1, BorderLayout.WEST);
panel1.add(textField1, BorderLayout.CENTER);
JPanel panel3 = new JPanel(new BorderLayout());
JLabel label3 = new JLabel("Numeric-only");
JTextField textField3 = new JTextField();
panel3.add(label3, BorderLayout.WEST);
panel3.add(textField3, BorderLayout.CENTER);
InputVerifier verifier = new InputVerifier()
public boolean verify(JComponent comp)
boolean returnValue;
JTextField textField = (JTextField)comp;
try
Integer.parseInt(textField.getText());
returnValue = true;
} catch (NumberFormatException e)
returnValue = false;
return returnValue;
textField1.setInputVerifier(verifier);
textField3.setInputVerifier(verifier);
frame.add(panel1, BorderLayout.NORTH);
//frame.add(panel2, BorderLayout.CENTER);
frame.add(panel3, BorderLayout.SOUTH);
frame.setSize(300, 95);
frame.setVisible(true);
}

Answer 1

thanx for ur answer but i think u donot understand i know how to display msg box i just want tha when i press enter then a msg box is displaayed that u leave a textfield empty or wrong entry
i store the text fields in a multidimentional array