填空题

程序运行结栗如下图：上边、左边和右边是三个按钮，下边是一个内容为“Class2804”的文本框txt。


import java.awt.*;
import javax.swing.*;
public class Class2804
{
public static void main(String[]args)
{
JFrame myWin=new JFrame("Class2804");
myWin.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
myWin.setBounds(100,200,300,200);
Container con=myWin.getContentPane();
con.setBackground(Color.red);
con.setLayout(new BorderLayout());
______
JButton button1=new JButton("左边");
JButton button2=new JButton("右边");
JButton button3=new JButton("上边");
con.add(button1,"West");
con.add(button2,"East");
con.add(button3,"North");
______
myWin.setVisible(true);
}
}