Show first 10 Fibonacci numbers in message dialog box with java code.

import javax.swing.*;

class Fibo

{

                public static void main(String[] args){

                int n1 = 0,n2 = 1,n3;

                String st;

                st = n1 + "\n" + n2 + "\n";

                for(int i = 1; i<10; i++){

                                n3 = n1 + n2;

                                st += ( n3 + "\n");

                                n1 = n2;

                                n2 = n3;

                }

                JOptionPane.showMessageDialog(null, st);

                System.exit(0);

                }                             

}