/*

<applet code="app3" height="400" width="400">

</applet>

*/

import java.applet.*;

import java.awt.*;

public class app3 extends Applet

{

int y=0;

boolean flag=true;

public void paint(Graphics g)

{

g.fillOval(150,y,75,75);

if(flag==false&&y!=0)

{

y--;

}

else if(flag==true&&y<325)

{

y++;

}

else if(y==325)

{

flag=false;

}

else if (flag==false&&y==0)

{

flag=true;

}

try

{

Thread.sleep(30);

}

catch(Exception e)

{}

repaint();

}

}