各位高手可不可以班我看看这个Delphi代码，编的是一个学生选课系统。
unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, Menus, Grids, DBGrids, DB, DBTables, ComCtrls, StdCtrls;

type
  TForm1 = class(TForm)
    MainMenu1: TMainMenu;
    N1: TMenuItem;
    NA11Students: TMenuItem;
    N3: TMenuItem;
    N4: TMenuItem;
    NAStudent: TMenuItem;
    NA11Courses: TMenuItem;
    NACourse: TMenuItem;
    NAddCourse: TMenuItem;
    NDelCourse: TMenuItem;
    NA11CS: TMenuItem;
    NDoCS: TMenuItem;
    NUnDoCS: TMenuItem;
    NCbyS: TMenuItem;
    NSbyC: TMenuItem;
    NDelStudent: TMenuItem;
    NAddStudent: TMenuItem;
    Label1: TLabel;
    StatusBar1: TStatusBar;
    StatusBar2: TStatusBar;
    Table_S: TTable;
    DataSource1: TDataSource;
    DBGrid1: TDBGrid;
    Table_C: TTable;
    QueryC_S: TQuery;
    TableC_S: TTable;
    procedure NA11StudentsClick(Sender: TObject);
    procedure NAStudentClick(Sender: TObject);
    procedure NAddStudentClick(Sender: TObject);
    procedure NDelStudentClick(Sender: TObject);
    procedure NA11CoursesClick(Sender: TObject);
    procedure NACourseClick(Sender: TObject);
    procedure NAddCourseClick(Sender: TObject);
    procedure NDelCourseClick(Sender: TObject);
    procedure NA11CSClick(Sender: TObject);
    procedure NDoCSClick(Sender: TObject);
    procedure NUnDoCSClick(Sender: TObject);
    procedure NCbySClick(Sender: TObject);
    procedure NSbyCClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation
uses Unit2;

{$R *.dfm}





unit Unit2;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, Buttons;

type
  TForm2 = class(TForm)
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    Edit1: TEdit;
    Edit2: TEdit;
    BitBtn1: TBitBtn;
    BitBtn2: TBitBtn;
    procedure FormShow(Sender: TObject);
    procedure BitBtn1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form2: TForm2;

implementation

{$R *.dfm}

procedure TForm2.FormShow(Sender: TObject);
begin
     Edit1.Clear;
     Edit2.Clear;
     Edit1.SetFocus;
end;

procedure TForm2.BitBtn1Click(Sender: TObject);
begin
    if Edit1.Text='' then
    begin
      showmessage(''''+Label2.Caption+'''不能为空!');
      Form2.ModalResult:=mrCancel;
      end
     else
     if Edit2.Text='' then
     begin
     showmessage(''''+Label3.Caption+'''不能为空!');
     Form2.ModalResult:=mrCancel;
end;

end;

我是菜菜鸟级人物。程序全完是案中案课本一步步搬上来的，可是编译后出现                                                         [Error] Unit2.pas(86): Declaration expected but end of file found                                                                            [Fatal Error] Unit1.pas(60): Could not compile used unit 'Unit2.pas'
麻烦告知下哪里出现了错误。调试不通过！！紧急，马上就要交作业了