the following applet is supposed to draw random lines on the screen, but
doesn't. does anyone know how to make it refresh?

thanks in advance

import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import java.util.*;
import java.text.*;
import java.lang.*;

public class UI2 extends Applet{
 private int x1,y1,x2,y2;

 public void init() {
   for(;;) {
     x1=(int)(Math.random()*100);
     y1=(int)(Math.random()*100);
     x2=(int)(Math.random()*100);
     y2=(int)(Math.random()*100);
     repaint();
   }
 }

 public void paint(Graphics g) {
   g.setColor(Color.black);

   g.drawLine(x1, y1, x2, y2);
 }

 public void update(Graphics g) {
   paint(g);
 }

}