Hi Friend,

Try the following code:
import java.io.*;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.util.*;

class StudentApplication {
JFrame f;
JPanel p1,p2,p3,p,p4;
JTabbedPane tp;
ImageIcon btnimg1,btnimg2;
JLabel l1, l2, l3, l4,l5,l6,l7,l8,l9,l10;
JTextField tf1,tf2,tf3,tf4,tf5,tf6,tf7,tf8,tf9,tf10;
JScrollPane sp1;
JButton savebtn,resetbtn,editbtn1,editbtn2,delBtn,viewBtn;
StudentApplication(){
f=new JFrame("Form");
p=new JPanel(new GridLayout(2,1));
p1=new JPanel(new GridLayout(5,2));
p2=new JPanel(new GridLayout(5,2));
p3=new JPanel(new GridLayout(2,2));
p4=new JPanel();
tp=new JTabbedPane();
l1=new JLabel("ID:");
l2=new JLabel("Name:");
l3=new JLabel("Age:");
l4=new JLabel("Notes:");
l5=new JLabel("Enter ID to delete Record:");
l7=new JLabel("ID:");
l8=new JLabel("Name:");
l9=new JLabel("Age:");
l10=new JLabel("Notes:");
tf1=new JTextField(12);
tf2=new JTextField(12);
tf3=new JTextField(12);
tf4=new JTextField(12);
tf5=new JTextField(12);
tf6=new JTextField(12);
tf7=new JTextField(12);
tf8=new JTextField(12);
tf9=new JTextField(12);
tf10=new JTextField(12);
savebtn=new JButton(" Add ");
resetbtn=new JButton(" Reset");
editbtn1=new JButton(" Edit ");
editbtn2=new JButton(" Save");
delBtn=new JButton("Delete");
viewBtn=new JButton("View");
final JTextArea area=new JTextArea(10,20);
final JScrollPane pane=new JScrollPane(area);
p1.add(l1);
p1.add(tf1);
p1.add(l2);
p1.add(tf2);
p1.add(l3);
p1.add(tf3);
p1.add(l4);
p1.add(tf4);
p1.add(savebtn);
p1.add(resetbtn);
p2.add(l7);
p2.add(tf7);
p2.add(l8);
p2.add(tf8);
p2.add(l9);
p2.add(tf9);
p2.add(l10);
p2.add(tf10);
p2.add(editbtn1);
p2.add(editbtn2);
p3.add(l5);
p3.add(tf5);
p3.add(delBtn);
p.add(p3);
p4.add(pane);
p4.add(viewBtn);
pane.setVisible(false);

resetbtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae){
tf1.setText("");
tf2.setText("");
tf3.setText("");
tf4.setText("");
}
});
savebtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae){
String value1=tf1.getText();
String value2=tf2.getText();
String value3=tf3.getText();
String value4=tf4.getText();
try{
File file=new File("school.txt");
FileWriter fstream = new FileWriter(file,true);
BufferedWriter out = new BufferedWriter(fstream);
out.write(value1+" "+value2+" "+value3+" "+value4);
out.newLine();
out.close();
JOptionPane.showMessageDialog(null,"Data is successfully inserted.");
}
catch(Exception e){}
}
});

continue..

delBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae){
File f1=new File("new.txt");
File f2=new File("school.txt");
try{
String value=tf5.getText();
BufferedWriter output= new BufferedWriter(new FileWriter(f1));
BufferedReader freader =new BufferedReader(new FileReader(f2));
String s;
while ((s=freader.readLine())!=null){
String []f = s.split(" ");
String id = f[0];
String name = f[1];
String c = f[2];
String note = f[3];
if (!id.equals(value) ){
output.write(s );
output.newLine();
}
}
freader.close();
output.close();
}
catch(Exception e){}
f2.delete();
f1.renameTo(f2);
}
});
editbtn1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae){
String value=tf7.getText();
File f=new File("school.txt");
try{
BufferedReader freader =new BufferedReader(new FileReader(f));
String s;
while ((s=freader.readLine())!=null){

String []st = s.split(" ");
String id = st[0];
String name = st[1];
String c = st[2];
String note = st[3];
if (id.equals(value) ){
tf7.setText(id);
tf8.setText(name);
tf9.setText(c);
tf10.setText(note);
}
}
freader.close();
}
catch(Exception e){}

}
});
editbtn2.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae){
String t1=tf7.getText();
String t2=tf8.getText();
String t3=tf9.getText();
String t4=tf10.getText();
File f3=new File("new.txt");
File f4=new File("school.txt");
try{

BufferedWriter output= new BufferedWriter(new FileWriter(f3));
BufferedReader freader =new BufferedReader(new FileReader(f4));
String s;
while ((s=freader.readLine())!=null){
String []f = s.split(" ");
String id = f[0];
String name = f[1];
String c = f[2];
String note = f[3];
if (!id.equals(t1) ){
output.write(s );
output.newLine();
}
}
freader.close();
output.write(t1+" "+t2+" "+t3+" "+t4);
output.close();
}
catch(Exception e){}
f4.delete();
f3.renameTo(f4);
}
});
viewBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae){
pane.setVisible(true);
try{
FileReader fr = new FileReader("school.txt");
BufferedReader myInput = new BufferedReader(fr);

String s;
StringBuffer b = new StringBuffer();
while ((s = myInput.readLine()) != null) {
b.append(s);
b.append("\n");
}
area.setText(b.toString());
}
catch(Exception e){}
}
});
f.getContentPane().add(tp);
tp.addTab("View Record",p4);
tp.addTab("Add Record",p1);
tp.addTab("Edit Record",p2);
tp.addTab("Delete Record",p);
f.setSize(450,180);
f.setVisible(true);
}
public static void main(String z[]){
StudentApplication app=new StudentApplication();
}
}
Hope that it will be helpful for you.
Thanks

The answer above..giving me the error of NoClassDefFoundError...