简答应用题

下面程序运行后，可以使用上下左右键移动组件。 补充下画线部分的代码。

import java.awt.*;

import java.awt.event.*;

public class E6 extends Frame implements keyListener

{

         TextField b1;

         int x,y;

         E6()

         {

                   setLayout (new FlowLayout());

                   b1 = new TextField("走");

                   __[1]__

                   b.addkeyListener(this);

                   setSize (200,120);

                   addWindowListener(new WindowListener()

                   {

                            public void windowClosing(WindowEvent e)

                              {

                                   System.exit(0);

                              }

                   });

         }

         public void keyPressed(KeyEvent e)

         {

                   x=b1.getBouds().x;

        y=b1.getBouds().y;

        if(e.getKeyCode()==__[2]__)

        {

           y=y-3;

           if(y<=1)y=50;

           b1.setLocation(x,y);

        }

        if(e.getkeyCode()==keyEven.VK_DOWN)

        {

           y=y+3;

           if(y>=100)y=50;

           b1.setLocation(x,y);

        }

        if(e.getkeyCode()==keyEvent.VK_LEFT)

        {

           x=x-3;

           if(x<=1)x=50;

           __[3]__;

        }

         if(e.getkeyCode()==keyEvent.VK_RIGHT)

           {

                    x=x+3;