Swing Program

import java.awt.*;
import java.sql.*;
import javax.swing.*;
import java.awt.event.*;
import java.util.regex.*;
class  ValidateData{

    public static void main(String[] args){
    JFrame f=new JFrame();
    JLabel label1=new JLabel("Name: ");
    JLabel label2=new JLabel("Marks: ");
    final JTextField text1=new JTextField(20);
    final JTextField text2=new JTextField(20);
    JButton b=new JButton("Check");
    text1.addKeyListener(new KeyAdapter(){
        public void keyReleased(KeyEvent e){
            String st=text1.getText();
         Pattern p = Pattern.compile("^[a-zA-Z]+$");
      Matcher m = p.matcher(st);
      if(!m.find()){
      JOptionPane.showMessageDialog(null, "Only characters A-Z, a-z are allowed!","Error!", JOptionPane.ERROR_MESSAGE);
      text1.setText("");
      }
     }
    });
    text2.addKeyListener(new KeyAdapter(){
        public void keyReleased(KeyEvent e){
            String st=text2.getText();
         Pattern p = Pattern.compile("(\\d)");
      Matcher m = p.matcher(st);
      if(!m.find()){
          JOptionPane.showMessageDialog(null, "Only numbers are allowed!", "Error!", JOptionPane.ERROR_MESSAGE);
       text2.setText("");
      }
     }
    });
    b.addActionListener(new ActionListener(){
        public void actionPerformed(ActionEvent e){
        String v1=text1.getText();
        String v2=text2.getText();
        JOptionPane.showMessageDialog(null,"Name is: "+v1+", Marks is: "+v2);
                 }
        });
        JPanel p=new JPanel(new GridLayout(3,2));
        p.add(label1);
        p.add(text1);
        p.add(label2);
        p.add(text2);
        p.add(b);
        f.add(p);
        f.setVisible(true);
        f.pack();
    }
}

import java.awt.*;
import java.sql.*;
import javax.swing.*;
import java.awt.event.*;
import java.util.regex.*;
class  ValidateData{

    public static void main(String[] args){
    JFrame f=new JFrame();
    JLabel label1=new JLabel("Name: ");
    JLabel label2=new JLabel("Marks: ");
    final JTextField text1=new JTextField(20);
    final JTextField text2=new JTextField(20);
    JButton b=new JButton("Check");
    text1.addKeyListener(new KeyAdapter(){
        public void keyReleased(KeyEvent e){
            String st=text1.getText();
         Pattern p = Pattern.compile("^[a-zA-Z]+$");
      Matcher m = p.matcher(st);
      if(!m.find()){
      JOptionPane.showMessageDialog(null, "Only characters A-Z, a-z are allowed!","Error!", JOptionPane.ERROR_MESSAGE);
      text1.setText("");
      }
     }
    });
    text2.addKeyListener(new KeyAdapter(){
        public void keyReleased(KeyEvent e){
            String st=text2.getText();
         Pattern p = Pattern.compile("(\\d)");
      Matcher m = p.matcher(st);
      if(!m.find()){
          JOptionPane.showMessageDialog(null, "Only numbers are allowed!", "Error!", JOptionPane.ERROR_MESSAGE);
       text2.setText("");
      }
     }
    });
    b.addActionListener(new ActionListener(){
        public void actionPerformed(ActionEvent e){
        String v1=text1.getText();
        String v2=text2.getText();
        JOptionPane.showMessageDialog(null,"Name is: "+v1+", Marks is: "+v2);
                 }
        });
        JPanel p=new JPanel(new GridLayout(3,2));
        p.add(label1);
        p.add(text1);
        p.add(label2);
        p.add(text2);
        p.add(b);
        f.add(p);
        f.setVisible(true);
        f.pack();
    }
}