import java.awt.*;
import java.applet.*;
import javax.swing.*;
import java.awt.*;
public class AnimationLine extends JApplet
{     
     public void init() 
     {
     getContentPane().add(new AnimationLinePanel()); 
     setSize(800,500);
     }
     public class AnimationLinePanel extends JPanel
     {
     int linex,linem = 1; 
     public AnimationLinePanel()
     {
     setBackground(Color.black); 
     }
     public void paintComponent(Graphics page)
     {
     super.paintComponent(page);
     page.setColor(Color.red); 
     page.drawLine(linem,200,310,400); 
     if(linex > 500)
	 {
     linem = -500;
	 page.setColor(Color.green); 
	 page.drawLine(linem,200,310,400);				 		
	 }
     if(linex < 0)
	 {
     linem = 600;
	 page.setColor(Color.yellow); 
	 page.drawLine(linem,200,310,400);				 
	 }
     linex += linem; 
     repaint(); 
     }
     }
}