use this code inside ur program

package rajanikant.code.oct_2008;

import java.awt.Container;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class SwingDate extends JFrame{

JTextField f1, f2;
JLabel l1,l2;
JPanel panel;
JButton calc = new JButton("Calculate");
public void calculate(){
Container container = getContentPane();
panel = new JPanel();
l1 = new JLabel("Date1");
f1 = new JTextField(15);
l2 = new JLabel("Date2");
f2 = new JTextField(15);
panel.add(l1);
panel.add(f1);
panel.add(l2);
panel.add(f2);
panel.add(calc);
container.add("Center", panel);
// setSize(new Dimension(50,50));
setVisible(true);
setSize(50, 100);
pack();

calc.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent e) {
String date1 = f1.getText();
String date2 = f2.getText();
try {
getDiffer(date1, date2);
} catch (ParseException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}

});

}
public void getDiffer(String dt1, String dt2) throws ParseException{

Date date1;// = new Date();
Calendar calendar = Calendar.getInstance();
SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy");
date1 = sdf.parse(dt1);
calendar.setTime(date1);
int cur_month = calendar.get(Calendar.MONTH)+1;
int cur_year = calendar.get(Calendar.YEAR);
int cur_date = calendar.get(Calendar.DATE);
String df1 = cur_date + "-" + cur_month + "-" + cur_year;


Date date2;
// String newdate = "19-07-2006";
date2 = sdf.parse(dt2);
calendar.setTime(date2);
int month = calendar.get(Calendar.MONTH)+1;
int year = calendar.get(Calendar.YEAR);
int date = calendar.get(Calendar.DATE);

String df2 = date + "-" + month + "-"+ year;

int day = 0;
int no_of_days = 0;
int flag = 0;
if (cur_year % 4 == 0) {

if (cur_year % 100 != 0) {
flag = 1;
}
else if (cur_year % 400 == 0) {
flag = 1;
}
else {
flag = 0;
}
}
// It is not divisible by 4.
else {
flag = 0;
}
if(cur_month == 2){
if(flag == 1){
no_of_days = 29;
}else{
no_of_days = 28;
}
}


if(cur_month == 1 || cur_month == 3 || cur_month == 5 || cur_month == 7 || cur_month == 8 || cur_month == 10 || cur_month == 12){
no_of_days = 31;
}
if(cur_month == 4 || cur_month == 6 || cur_month == 9 || cur_month == 11){
no_of_days = 30;
}
if(cur_date > date){
day = cur_date - date;
}else{
day = cur_date - date + no_of_days;
cur_month = cur_month - 1;
}

if(cur_month > month){
cur_month = cur_month - month;
}else{
cur_month = cur_month - month + 12;
cur_year = cur_year - 1;
}
if(cur_year > year){
cur_year = cur_year - year;
}else{
cur_year = 0;
}
String diff = "Difference Between " + df1 + " and " + df2 + " is : " +cur_year + " Year " + cur_month + " Month " +day + " Days";
JOptionPane.showMessageDialog(this,diff);
}
public static void main(String s[]){
new SwingDate().calculate();
}
}

Rajanikant