这个java有好几个错,怎么改?

import java.awt.*;
import java.awt.event.*;

public class Lab10 {
public static void main(String[] arg) {
new fil();
}
}

class fil extends WindowAdapter implements ActionListener {
MenuBar mb;

Menu mn1, mn2, mn3, mn4;

MenuItem mi1a, mi1b, mi1c, mi2a, mi2b, mi3, mi4;

public fil() {
Frame f = new Frame("wo de file");
mb = new MenuBar();
mn1 = new Menu("File");
mn2 = new Menu("Input Information");
mn3 = new Menu("Display Information");
mn4 = new Menu("Close");
mi1a = new MenuItem("New");
mi1b = new MenuItem("Open");
mi1c = new MenuItem("Save");
mi2a = new MenuItem("Input name");
mi2b = new MenuItem("Input age");
mi3 = new MenuItem("Display Information");
mi4 = new MenuItem("Close");