那儿错了？

[Hollower]

import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
public class menudemo extends Applet implements ActionListener
{
Button button1,button2;
MenuFrame menuWindow;
public void init()
{
button1=new Button("Show window");
add(button1);
button1.addActionListener(this);
button2=new Button("Hide window");
add(button2);
button2.addActionListener(this);
menuWindow=new MenuFrame("Demo Menu Window");
menuWindow.setSize(100,100);
}
public void actionPerformed(ActionEvent event)
{
if(event.getSource()==button1)
{
menuWindow.setVisible(true);
}
if(event.getSource()==button2)
{
menuWindow.setVisible(false);
}
}
}
class MenuFrame extends Frame implements ActionListener
{
Menu Menu1;
MenuBar Menubar1;
MenuItem menuitem1,menuitem2,menuitem3;
TextField text1;
MenuFrame(String title)
{
super(title);
text1=new TextField(20);
setLayout(new GridLayout(1,1));
add(text1);
Menubar1=new MenuBar();
Menu1=new Menu("File");
menuitem1=new MenuItem("Hello");
Menu1.add(menuitem1);
menuitem1.addActionListener(this);
menuitem2=new MenuItem("From");
Menu1.add(menuitem2);
menuitem2.addActionListener(this);
menuitem3=new MenuItem("Java");
Menu1.add(menuitem3);
menuitem3.addActionListener(this);
Menubar1.add(Menu1);
setMenuBar(Menubar1);
}
public void actionPerformed(ActionEvent event)
{
if(event.getSource()==menuitem1)
{
text1.setText("Hello");
}
if(event.getSource()==menuitem2)
{
text1.setText("From");
}
if(event.getSource()==menuitem3)
{
text1.setText("Java");
}
}
}
错误：
menudemo.java:44: cannot resolve symbol
symbol : constructor Menu (java.lang.String)
location: class Menu
Menu1=new Menu("File");
^
menudemo.java:46: cannot resolve symbol
symbol : method add (java.awt.MenuItem)
location: class Menu
Menu1.add(menuitem1);
^
menudemo.java:49: cannot resolve symbol
symbol : method add (java.awt.MenuItem)
location: class Menu
Menu1.add(menuitem2);
^
menudemo.java:52: cannot resolve symbol
symbol : method add (java.awt.MenuItem)
location: class Menu
Menu1.add(menuitem3);
^
menudemo.java:54: add(java.awt.Menu) in java.awt.MenuBar cannot be applied to
(M
enu)
Menubar1.add(Menu1);
5 errors