import java.awt.*; public class Earthquake extends java.applet.Applet{ public DrawSim plot; public Simulation sim; public Controls usercontrols; public Thread runner; public void init(){ setLayout(new BorderLayout()); plot = new DrawSim(); sim = new Simulation(plot,this); usercontrols = new Controls(this,sim); add("Center",plot); add("South",usercontrols); } public void start(){ runner = new Thread(sim); runner.start(); } public void stop(){ if(runner!=null) runner.stop(); } }