public class h2_button extends Applet implements ActionListener {

Button b_next;
Color c;

public void init() {

b_next=new Button("Next one !");
add(b_next);
b_next.addActionListener(this);

int rval = (int)Math.floor(Math.random() * 256);
int gval = (int)Math.floor(Math.random() * 256);
int bval = (int)Math.floor(Math.random() * 256);
c = new Color(rval,gval,bval);
}

public void actionPerformed(ActionEvent e) {
Object o_source=e.getSource();
if(o_source==b_next) {
int rval = (int)Math.floor(Math.random() * 256);
int gval = (int)Math.floor(Math.random() * 256);
int bval = (int)Math.floor(Math.random() * 256);
c = new Color(rval,gval,bval);
repaint();
}
}

public void paint (Graphics g) {
int r_w=140;
int r_h=120;
Color grau = new Color(220,220,220);
g.setColor(Color.white);
g.fillRect(0,0,r_w,r_h);
g.setColor(grau);
g.drawRect(0,0,r_w-1,r_h-1);

g.setColor(c);
g.fillRect(40,50,60,45);
g.setColor(grau);
g.drawRect(40,50,60,45);

}
}