public class test extends Applet
{
 public void init()
 {
  Container cp=getContentPane();
  cp.setLayout(new FlowLayout());
  JButton B1=new JButton("开始");
  JButton B2=new JButton("停止");
  cp.add(B1);
  cp.add(B2);
 }
}

编译是错误如下:

D:\j2sdk1.4.0\bin>javac test.java
test.java:22: cannot resolve symbol
symbol  : method getContentPane  ()
location: class test
                Container cp=getContentPane();
                             ^
1 error
请问如何解决？